[tick] n [ME tyke, teke; akin to MHG zeche tick, Arm tiz] (14c) 1: any of a superfamily (Ixodoidea of the order Acarina) of bloodsucking arachnids that are larger than the related mites, attach themselves to warm-blooded vertebrates to feed, and include important vectors of infectious diseases
2: any of various usu. wingless parasitic dipteran flies--compare sheep ked
[2]tick n [ME tike, prob. fr. MD (akin to OHG ziahha tick), fr. L theca cover, fr. Gk theke case; akin to Gk tithenai to place--more at do] (15c) 1: the fabric case of a mattress, pillow, or bolster; also: a mattress consisting of a tick and its filling
2: ticking [3]tick n [ME tek pat, light stroke; akin to MHG zic light push] (1680) 1 a: a light rhythmic audible tap or beat; also: a series of such ticks b chiefly Brit: the time taken by the tick of a clock: moment
2: a small spot or mark; esp: one used to direct attention to something, to check an item on a list, or to represent a point on a scale [4]tick vi (1721) 1: to make the sound of a tick or a series of ticks
2: to operate as a functioning mechanism: run "tried to understand what made him ~" "the motor was ~ing over quietly" ~ vt 1: to mark with a written tick: check--usu. used with off "~ed off each item in the list"
2: to mark, count, or announce by or as if by ticking beats "a meter ~ing off the cab fare"
3: to touch with a momentary glancing blow "~ed the ball" [5]tick n [short for [1]ticket] (1642) chiefly Brit: credit, trust; also: a credit account