FIL'LIP, verb transitive [probably from the root of Latin pello, like pelt. See Filly.] To strike with the nail of the finger, first placed against the ball of the thumb, and forced from that position with some violence. FIL'LIP, noun a jerk of the finger forced suddenly from the thumb.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI