Hydrachnid

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Hydrachnid \Hy*drach"nid\, n. [Hydr- + arachnid.] (Zool.)
     An aquatic mite of the genus {Hydrachna}. The hydrachnids,
     while young, are parasitic on fresh-water mussels.
     [1913 Webster]