c. 1300, "a skirmish," verbal noun from bicker (v.). Meaning "a verbal wrangle" is from 1570s.
bickering (adj.)
1808 in the sense of "contentious," present-participle adjective from bicker (v.). Earlier it was used to mean "flashing, quivering" (1660s).
bicep
bicephalous
biceps
bicipital
bicker
bickering
bicoastal
bicuspid
bicycle
bicycling
bicyclist