The Collaborative International Dictionary of English v.0.48:

Chlamydiaceae \Chlamydiaceae\ prop. n.
   A natural family of gram-negative bacteria which are
   parasites in warm-blooded vertebrates.

   Syn: family Chlamydiaceae.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Chlamydiaceae
    n 1: Gram-negative parasites in warm-blooded vertebrates [syn:
         Chlamydiaceae, family Chlamydiaceae]