Real Dictionary

flicker
If you experience a flicker of emotion, you feel that emotion only for a very short time, and not very strongly.
verb: If a light or flame flickers, it shines unsteadily.
verb: If an expression flickers across your face, it appears very briefly.
verb: If someone's eyes flicker towards something, they look at it quickly.
verb: If something flickers, it makes very slight, quick movements.

flicker in American English 1
an act or instance of flickering
to cause to flicker or waver
to flap the wings rapidly, as in hovering; flutter
intransitive verb: to burn unsteadily; shine with a wavering light
noun: an unsteady flame or light
transitive verb: to cause to flicker

flicker in American English 2
any of several North American woodpeckers (genus Colaptes); esp., the yellow-shafted flicker
noun: any of several American woodpeckers of the genus Colaptes, having the underside of the wings and tail brightly marked with yellow or red and noted for taking insects from the ground as well as trees

flicker in British English 1
noun: an unsteady or brief light or flame
verb: to shine with an unsteady or intermittent light

flicker in British English 2
noun: any North American woodpecker of the genus Colaptes, esp C. auratus (yellow-shafted flicker), which has a yellow undersurface to the wings and tail