early 13c., picken "to peck;" c. 1300, piken "to work with a pick," probably representing a fusion of Old English *pician "to prick," (implied by picung "a piercing, pricking," an 8c. gloss on Latin stigmata) with Old Norse pikka "to prick, peck," both from a Germanic root (source also of Middle Dutch picken, German picken "to pick, peck"), perhaps imitative. Influence from Middle French piquer "to prick, sting" (see pike (n.2)) also is possible, but that French word generally is not considered a source of the English word. Related: Picked; picking.
Meaning "to eat with small bites" is from 1580s. The meaning "to choose, select, pick out" emerged late 14c., from earlier meaning "to pluck with the fingers" (early 14c.). Sense of "to rob, plunder" (c. 1300) weakened to a milder sense of "steal petty things" by late 14c. Of forcing locks with a pointed tool, by 1540s. Meaning "to pluck (a banjo)" is recorded from 1860. To pick a quarrel, etc. is from mid-15c.; to pick at "find fault with" is from 1670s. Pick on "single out for adverse attention" is from late 14c.; pick off "shoot one by one" is recorded from 1810; baseball sense of "to put out a runner on base" is from 1939. Also see pick up. To pick and choose "select carefully" is from 1660s (choose and pick is attested from c. 1400).