1a parasitic arachnid which attaches itself to the skin of a terrestrial vertebrate from which it sucks blood, leaving the host when sated. Some species transmit diseases, including tularaemia and Lyme disease.
Suborder Ixodida, order Acari (or order and subclass)
informal a parasitic louse fly, especially the sheep ked.
2British informal a worthless or contemptible person:he was shown up in court for the little tick that he was
full (or tight) as a tick
informal replete after eating (or very drunk):I’ve never risen from the table after a feed anything less than full as a tick
Old Englishticia, of Germanic origin; related to Dutch teek and German Zecke