n. 1. very small free-living arachnid that is parasitic on animals or plants; related to ticks. [ WordNet 1.5 ]

n. 1. the family of arachnids of the order Acarina consisting of mites.
Syn. -- family Acaridae. [ WordNet 1.5 ]

n. [ See Acarus. ] (Zool.) One of a group of arachnids, including the mites and ticks. [ 1913 Webster ]