Rissoid

1 definition found

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

  Rissoid \Ris"soid\, n. [NL. Rissoa, the typical genus ( fr. A.
     Risso, an Italian naturalist) + -oid.] (Zool.)
     Any one of very numerous species of small spiral gastropods
     of the genus {Rissoa}, or family {Rissoidae}, found both in
     fresh and salt water.
     [1913 Webster]