Merriam-Webster Collegiate Dictionary - tick

 I. noun  Etymology: Middle English tyke, teke; akin to Middle High German zeche ~, Armenian tiz  Date: 14th century  1. any of a superfamily (Ixodoidea) of bloodsucking acarid 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 usually wingless parasitic dipteran flies — compare sheep ked  II. noun  Etymology: Middle English tike, probably from Middle Dutch (akin to Old High German ziahha ~), from Latin theca cover, from Greek theke case; akin to Greek tithenai to place — more at do  Date: 15th century  1. the fabric case of a mattress, pillow, or bolster; also a mattress consisting of a ~ and its filling  2. ~ing I  III. noun  Etymology: Middle English tek pat, light stroke; akin to Middle High German zic light push  Date: 1680  1.  a. a light rhythmic audible tap or beat; also a series of such ~s  b. the time taken by the ~ of a clock ; moment  2. a small spot or mark; especially one used to direct attention to something, to check an item on a list, or to represent a point on a scale  IV. verb  Date: 1721  intransitive verb  1. to make the sound of a ~ or a series of ~s  2. to operate as a functioning mechanism ; run tried to understand what made him ~ the motor was ~ing over quietly  transitive verb  1. to mark with a written ~ ; check — usually used with off ~ed off each item in the list  2. to mark, count, or announce by or as if by ~ing beats a meter ~ing off the cab fare  3. to touch with a momentary glancing blow ~ed the ball  V. noun  Etymology: short for 1~et  Date: 1642 chiefly British credit, trust; also a credit account