- indigo[indigo 词源字典]
- indigo:  Etymologically indigo, a blue dye, is the ‘Indian dye’ – so named because supplies of it were obtained from India. The term is an ancient one. It originated in Greek indikón, literally the ‘Indian substance’, a derivative of the adjective Indikós ‘Indian’, and passed via Latin indicum and Spanish indico into English as indico.
This was replaced in the 17th century by the Portuguese form indigo, and it was Portuguese influence, stemming from their commercial activities in India, that really established the term among the European languages (hitherto the commoner term for the dye had been anil, a word of Sanskrit origins). (The name India, incidentally, to which indigo is related, comes ultimately from Old Persian hiñd’u, which originally meant ‘river’, was subsequently applied specifically to the river Indus, and finally became the name for the country through which the Indus flowed.)
=> india[indigo etymology, indigo origin, 英语词源]
- individual:  To begin with, individual retained in English its ancestral meaning ‘not able to be divided’: ‘in the name of the holy and individual Trinity’. Richard Whitbourne, Discourse and Discovery of Newfoundland 1623. It was borrowed from medieval Latin indīviduālis, a derivative of Latin indīviduus ‘not divisible’, which in turn was based on dīviduus, a derivative of the verb dīvidere ‘divide’. The semantic move from ‘not divisible’ to ‘single, separate’ took place in the 17th century. (English acquired the formally parallel indivisible, incidentally, in the 14th century.)
- indolent:  Historically, indolent means ‘feeling no pain’ – indeed, that is how it was used as a technical medical term in English in the 17th and 18th centuries. It comes from late Latin indolens, which was based on the Latin verb dolere ‘suffer pain’ (source also of English dolour  and doleful ). English took the term directly from Latin, but meanwhile in French indolent had broadened out in meaning via ‘insensitive’ to ‘inactive, lethargic, lazy’, and that is the basis of the current English use of the adjective, acquired in the early 18th century.
=> doleful, dolour
- indomitable: see tame
- indulge:  The -dulg- of indulge may be related to such words as Greek dolikhós and Russian dólgij, meaning ‘long’. In that case Latin indulgēre, the immediate source of the English word, may to begin with have signified ‘allow long enough for’. Its only recorded senses, however, are the same as those of modern English indulge.
- industry:  Industry comes, partly via Old French industrie, from Latin industria, which meant ‘quality of being hard-working, diligence’. This was a derivative of the adjective industrius ‘diligent’, which went back to an Old Latin indostruus, formed from the prefix indu- ‘in’ (see INDIGENOUS) and the element -struus (a relative of the verb struere ‘build’, from which English gets construct, destroy, etc).
=> construct, destroy, structure
- inebriate:  Latin ēbrius (a relative of sōbrius, from which English gets sober) meant ‘drunk’. From it was formed the verb ēbriāre ‘intoxicate’, which with the addition of the intensive prefix in- produced inēbriāre ‘make very drunk’ – whence English inebriate.
- ineffable:  Ineffable literally means ‘that cannot be spoken’. Its ultimate source was the Latin verb fārī ‘speak’, which has also given English fable, fame, fate, etc. Addition of the prefix ex- ‘out’ produced effārī ‘speak out’, from which the adjective ineffābilis was derived. In 19th-century English the word was used as a plural noun, like unmentionables, as a humorous euphemism for ‘trousers’ or ‘nether garments’: ‘shoes off, ineffables tucked up’, William Cory, Letters and Journals 1867.
=> fable, fame, fate
- inert:  The -ert of inert is the same word as art. The word comes from Latin iners, which originally meant ‘unskilled’, but soon developed semantically to ‘inactive’. It was formed with the negative prefix in- from ars ‘skill’, source of English art. The derivative inertia  is a Latin formation. In classical times it meant simply ‘lack of skill, idleness’; it was Johannes Kepler who first used it as a technical term in physics in the 17th century.
=> art, inertia
- inevitable:  Latin ēvītāre meant ‘avoid’. It was a compound verb formed from the prefix ex- ‘away, from’ and vītāre ‘shun’, and actually produced an English verb evite ‘avoid’, a scholarly 16th-century introduction which survived as an archaism into the 19th century. Its derived adjective was ēvītābilis ‘avoidable’, which with the negative prefix became inēvītābilis.
- inexorable:  Etymologically, inexorable means ‘that cannot be removed by praying’. It is an adjective of many layers, of which the original is Latin ōrāre ‘pray’ (source of English oracle, orator, etc). Addition of the prefix ex- ‘out’ produced exōrāre ‘remove by pleading or entreating’, and further prefixation and suffixation gave inexōrābilis, which entered English partly via French inexorable.
=> oracle, orator
- infamous:  The negative connotations of infamous go back a long way – to the word’s source, in fact, Latin infāmis. This did not mean simply ‘not well known’; the prefix in- denoted positively ‘bad’, and so infāmis signified ‘of ill repute’. In post-classical times infāmis became infamōsus, which passed into English as infamous.
- infant:  Etymologically, an infant is ‘someone who cannot yet speak’. The word comes via Old French enfant from Latin infāns ‘young child’, a noun use of the adjective infāns, originally ‘unable to speak’, which was formed from the negative prefix in- and the present participle of fārī ‘speak’ (source of English fable, fame, fate, etc).
The somewhat improbable derivative infantry  comes via French from Italian infanteria; this was based on infante, whose original meaning ‘young person’ had shifted to ‘foot soldier’ (a development distantly reminiscent of the use of British English lads for ‘male members of a group, team, etc’).
=> fable, fame, fate
- infect:  Latin inficere originally meant ‘put in’ – it was a compound verb formed from the prefix in- and facere ‘put, do’ (source of English fact, fashion, etc). Its earliest specialized extension was ‘dip in’, which was applied specifically to the dipping of cloth into dye. From this it moved on to ‘stain’, and then it was a short step to ‘taint, spoil’. ‘Affect with disease’ was a post-Latin development. English acquired the word via the Latin past participial stem infect-.
=> fact, factory, fashion, perfect
- inferior: see under
- inferno:  Etymologically, an inferno is that which is ‘below’. The word comes ultimately from Latin infernus, meaning ‘situated below, subterranean’. In ancient mythology, the nether regions were the abode of the dead, so inferna came to be used as the equivalent of Dis, and the Greek Hades. In Jewish and Christian belief, this basement area was the realm of evil spirits, and consequently in late Latin infernus came to cover much the same semantic ground as English hell.
In Italian this became inferno, and English adopted it (strongly under the influence of the Inferno of Dante’s Divine Comedy) in that form in the early 19th century. Its metaphorical use for ‘intense heat’, inspired by the stereotypical flames of hell, is a comparatively recent development. Meanwhile the related infernal  (from late Latin infernalis) had long since taken up residence in English, and by the 18th century was being used as an expletive (as in ‘their infernal cheek’).
- inflate:  Inflate comes from inflātus, the past participle of Latin inflāre ‘blow into’. This was a compound verb formed from the prefix in- and flāre ‘blow’ (a distant relative of English blow). The use of inflate and inflation as technical terms in economics to denote uncontrolled growth in money supply, credit, etc originated in 1830s America.
- inflict: see profligate
- influence:  Influence began life as an astrological term. It was coined in medieval Latin as influentia from the present participle of Latin influere ‘flow in’, a compound verb based on fluere ‘flow’, and to begin with denoted a sort of fluid that was supposed to be given off by the stars and to influence human life. English originally acquired the word with this meaning, and it was not until the end of the 16th century that the main current sense ‘power to produce effects’ started to establish itself.
The more concrete notion of an ‘emanation’ that affected people also lay behind the use of Italian influenza for ‘epidemic’, from which English got influenza (see FLU). Another English acquisition from Latin influere is influx , which comes from its past participle.
=> flu, fluent, influx
- influenza: see flu