Merriam-Webster Collegiate Dictionary - chlamydia

 noun  (plural ~e)  Etymology: New Latin, from Greek chlamyd-, chlamys  Date: 1966  1. any of a genus (Chlamydia, family Chlamydiaceae) of spherical gram-negative intracellular bacteria; especially one (C. trachomatis) that causes or is associated with various diseases of the eye and urogenital tract including trachoma, lymphogranuloma venereum, cervicitis, and some forms of urethritis  2. a disease or infection caused by ~e  • ~l adjective