tick

1. intransitive verb

2. 1 :  to make the sound of a tick or a series of ticks

3. 2 :  to operate as a functioning mechanism :  run tried to understand what made him tick the motor was ticking over quietly

4. transitive verb

5. 1 :  to mark with a written tick :  check —usually used with off ticked off each item in the list

6. 2 :  to mark, count, or announce by or as if by ticking beats a meter ticking off the cab fare

7. 3 :  to touch with a momentary glancing blow ticked the ball

1. 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. 2 :  any of various usually wingless parasitic dipteran flies — compare sheep ked

1. 1 :  the fabric case of a mattress, pillow, or bolster; also :  a mattress consisting of a tick and its filling

2. 2 :  ¹ticking

chiefly British

1. :  credit, trust; also :  a credit account

1. 1 :  a light rhythmic tap or beat (as of a clock)

2. 2 :  a small mark used chiefly to draw attention to something or to check an item on a list

1. 1 :  to make a light rhythmic tap or a series of light rhythmic taps a ticking clock

2. 2 :  to mark, count, or announce by or as if by light rhythmic taps A meter ticked off the cab fare.

3. 3 :  ²check 5 She ticked off each item in the list.

4. 4 :  operate 1, function The old car is still ticking.

1. :  a tiny animal with eight legs that is related to the spider and attaches itself to humans and animals from which it sucks blood

1. 1:  any of numerous bloodsucking arachnids that constitute the acarine superfamily Ixodoidea, are much larger than the closely related mites, attach themselves to warm-blooded vertebrates to feed, include important vectors of various infectious diseases of humans and lower animals, and although the immature larva has but six legs, may be readily distinguished from an insect by the complete lack of external segmentation

2. 2:  any of various usually wingless parasitic dipteran flies (as the sheep ked)