fillip

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A snap or light blow made by pressing a fingertip against the thumb and suddenly releasing it.
2. n. An embellishment that excites or stimulates: "Spritely tabasco onions, just a little crunch for the top, were an added fillip” ( Alison Arnett).
3. n. One that is trivial or of little importance.
4. v. To strike or propel rapidly by as or as if by a fillip: filliped his finger against my ear; filliped the pretzel across the counter.
5. v. To stimulate or arouse.

Century Dictionary and Cyclopedia

1. To strike slightly or with some light instrument; especially, to strike with the nail of a finger first bent against the ball of the thumb, and let fly from that position with some force.
2. To strike, nudge, or touch, as a horse or a person, in order to urge or press forward; incite; drive.
3. To strike or tap with the nail of the finger.
4. n. A jerk of a finger bent against the ball of the thumb, and then suddenly let fly; hence, a smart tap or stroke.
5. n. Anything which tends to rouse, excite, or revive: as, that acted as a fillip to my spirits.

Wiktionary

1. n. archaic A flick; the act of releasing the index finger from the hold of a thumb with a snap.
2. n. Something that excites or stimulates.
3. v. transitive To strike or project with the nail of a finger snapped from the end of the thumb; flick.
4. v. transitive To tap or strike smartly.
5. v. transitive To make a fillip; drive by or as by a fillip; stimulate; excite; whet.

GNU Webster's 1913

1. v. To strike with the nail of the finger, first placed against the ball of the thumb, and forced from that position with a sudden spring; to snap with the finger.
2. v. To snap; to project quickly.
3. n. A jerk of the finger forced suddenly from the thumb; a smart blow.
4. n. Something serving to rouse or excite.

WordNet 3.0

1. n. anything that tends to arouse