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 ]