impedeyoudaoicibaDictYouDict[impede 词源字典]
impede: see pedal
[impede etymology, impede origin, 英语词源]
impend: see pendulum
imperative: see empire
imperial: see empire
impersonate: see person
impetuous: [14] Etymologically, impetuous means ‘having impetus’. It comes from Latin impetuōsus, a derivative of the noun impetus ‘attack’ (source of English impetus [17]), which in turn was based on impetere ‘attack’. This was a compound verb formed from the prefix in- ‘against’ and petere ‘go towards, seek, attack’ (source of English appetite, compete, perpetuate, petition, petulant, and repeat).

The etymological idea underlying both words is thus of ‘rushing towards something with great violence or aggression’. Another member of the same family is impetigo [16], the name of a sort of skin disease. This was borrowed from Latin impetīgō, whose medical meaning was a specialization of an earlier and much more general ‘attack’ (as in ‘an attack of eczema’).

=> appetite, compete, impetus, perpetuate, petulant, repeat
implacable: see please
implement: [15] The idea underlying implement is of ‘filling up’. It comes ultimately from Latin implēre, a compound verb formed from the intensive prefix in- and plēre ‘fill’ (as in English complete). This originally meant ‘fill up’, and hence ‘fulfil’, but in post-classical times, under the influence of implicāre (source of English employ) it came to mean ‘use, employ’, and so the derived plural noun implēmenta denoted ‘things used, equipment’.

It was originally used in the plural in English too, and it was not until the 16th century that the singular ‘tool’ emerged. The original Latin sense ‘fulfil’ is preserved much more closely in the verb implement, which was an independent and considerably later introduction, first recorded in Scottish English in the 19th century. (From the same source come English complement and supplement.)

=> complement, complete, supplement
implicate: see employ
implore: see explore
imply: see employ
important: [16] Important and import (the opposite of export) come from the same source – Latin importāre, a compound verb formed from the prefix in- and portāre ‘carry’ (as in English portable). Its original literal sense (as represented in the English verb import [16]) was ‘bring in’, but in the Middle Ages this developed metaphorically to ‘imply, mean’ (which is what French importer and Italian importare signify), and its present participle importāns gave English important.
=> import, port, portable
impostor: [16] An impostor is etymologically someone who ‘imposes’ on others. The word comes via French imposteur from late Latin impostor, a contraction of classical Latin impositor. This was a derivative of imponere ‘put on’, hence ‘inflict, deceive’ (a compound verb based on ponere ‘put, place’), which also gave English impose [15], impost ‘tax’ [16], and imposture [16]. It is the ‘deceive’ sense of imponere, of course, that has come through into impostor.
=> compose, depose, impose, position
imprecation: see pray
impregnable: see prey
impresario: [18] Impresario has no etymological connection with ‘impressing’ people (often though it is mistakenly spelled impressario). It was borrowed from Italian, where it was a derivative of impresa ‘undertaking’. This in turn came from the verb imprendere ‘undertake’, which goes back to a hypothetical Vulgar Latin *imprendere (source of the archaic English emprise ‘enterprise’ [13]), a compound based on Latin prendere ‘take’. Hence an impresario is literally someone who ‘undertakes’ something.
impress: see press
improve: [16] The -prove of improve has no direct connection with the verb prove, although the two have come to resemble each other over the centuries. It comes ultimately from late Latin prōde ‘advantageous’ (source of English proud). This gave Old French prou ‘profit’, which was combined in Anglo-Norman with the causative prefix em- to produce the verb emprouer. This originally meant ‘turn to a profit, turn to one’s advantage’, a sense which survives in English in one or two fossilized contexts such as ‘improve the shining hour’. Modern English ‘make or get better’ developed in the 17th century.
=> proud
improvise: [19] Etymologically, if you improvise something, it is because it has not been ‘provided’ for in advance. The word comes via French improviser from the Italian adjective improvviso ‘extempore’, a descendant of Latin imprōvīsus ‘unforeseen’. This in turn was formed from the negative prefix in- and the past participle of prōvīdere ‘foresee’ (source of English provide).

The earliest recorded use of the verb in English is by Benjamin Disraeli in Vivian Grey 1826: ‘He possessed also the singular faculty of being able to improvise quotations’. (The closely related improvident ‘not providing for the future’ [16] preserves even more closely the sense of its Latin original.)

=> provide
impugn: see pugnacious