(n)a tick that feeds on dusky-footed wood rat and bites humans; principal vector for Lyme disease in western United States especially northern California, Syn.western black-legged tick
(n)parasitic on mice of genus Peromyscus and bites humans; principal vector for Lyme disease in eastern United States (especially New England); northern form was for a time known as Ixodes dammini (deer tick), Syn.black-legged tick