early 14c., from Old English arwan, earlier earh "arrow," possibly borrowed from Old Norse ör (genitive örvar), from Proto-Germanic *arkhwo (source also of Gothic arhwanza), from PIE root *arku-, source of Latin arcus (see arc (n.)). The ground sense would be "the thing belonging to the bow." Meaning "a mark like an arrow" in cartography, etc. is from 1834.
A rare word in Old English. More common words for "arrow" were stræl (which is cognate with the word still common in Slavic and once prevalent in Germanic, related to words meaning "flash, streak") and fla, flan (the -n perhaps mistaken for a plural inflection), from Old Norse, a North Germanic word, perhaps originally with the sense of "splinter." Stræl disappeared by 1200; fla became flo in early Middle English and lingered in Scottish until after 1500.
Robyn bent his joly bowe,
Therein he set a flo.
["Robyn and Gandelyn," in a minstrel book from c. 1450 in the British Museum]
small northern constellation representing an arrow, 1704, from Latin sagitta "arrow" (see Sagittarius).
1540s, "shaped like or resembling an arrow or arrowhead," as if from Latin *sagittalis, from sagitta "arrow" (see Sagittarius).
mid-14c., "make a notch in;" 1510s, "fit (the nock of an arrow) to a bowstring;" from nock (n.). Related: Nocked; nocking.