Merriam-Webster Collegiate Dictionary - flicker

 I. verb  (~ed; ~ing)  Etymology: Middle English flikeren, from Old English flicorian  Date: before 12th century  intransitive verb  1. to move irregularly or unsteadily ; flutter  2. to burn or shine fitfully or with a fluctuating light a candle ~ing in the window  3. to appear briefly  transitive verb  1. to cause to ~  2. to produce by ~ing  • ~ingly adverb  II. noun  Date: 1822  1.  a. an act of ~ing  b. a sudden brief movement  c. a momentary quickening a ~ of anger  d. a slight indication ; hint a ~ of recognition  2.  a. a wavering light  b. a repeated momentary defect in a cathode-ray tube image caused especially by slow scanning of the screen  3. movie — often used in plural  • ~y adjective  III. noun  Etymology: probably imitative of its call  Date: 1809 a large barred and spotted North American woodpecker (Colaptes auratus) with a brown back that commonly forages on the ground for ants — compare red-shafted ~, yellow-shafted ~