From The Collaborative International Dictionary of English v.0.48 :
Cimex \Ci"mex\, n.; pl. Cimices. [L., a bug.] (Zool.)
A genus of hemipterous insects of which the bedbug is the
best known example. See Bedbug.
[1913 Webster]
From WordNet (r) 3.0 (2006) :
Cimex
n 1: type genus of the Cimicidae: bedbugs [syn: Cimex, genus
Cimex]