arrow: [OE] Appropriately enough, the word arrow comes from the same ultimate Indo- European source that produced the Latin word for ‘bow’ – *arkw-. The Latin descendant of this was arcus (whence English arc and arch), but in Germanic it became *arkhw-. From this basic ‘bow’ word were formed derivatives in various Germanic languages meaning literally ‘that which belongs to the bow’ – that is, ‘arrow’ (Gothic, for instance, had arhwazna).
The Old English version of this was earh, but it is recorded only once, and the commonest words for ‘arrow’ in Old English were strǣl (still apparently in use in Sussex in the 19th century, and related to German strahl ‘ray’) and fiān (which remained in Scottish English until around 1500). Modern English arrow seems to be a 9th-century reborrowing from Old Norse *arw-. => arc, arch
early 14c., from Old English arwan, earlier earh "arrow," possibly borrowed from Old Norse ör (genitive örvar), from Proto-Germanic *arkhwo (cognates: Gothic arhwanza), from PIE root *arku- "bow and/or arrow," source of Latin arcus (see arc (n.)). The ground sense would be "the thing belonging to the bow," perhaps a superstitious avoidance of the actual name.
A rare word in Old English, where more common words for "arrow" were stræl (cognate with the word still common in Slavic, once prevalent in Germanic, too; meaning related to "flash, streak") and fla, flan, a North Germanic word, perhaps originally with the sense of "splinter." Stræl disappeared by 1200; fla lingered in Scottish until after 1500. Meaning "a mark like an arrow in cartography, etc." is from 1834.
Robyn bent his joly bowe,
Therein he set a flo.
["Robyn and Gandelyn," in minstrel book, c. 1450, in British Museum]