any Gram-negative bacteria of the genus Chlamydia, which are obligate intracellular parasites and are responsible for such diseases as trachoma, psittacosis, and some sexually transmitted diseases
Word origin
C20: New Latin, from Greek khlamus mantle + -ia
chlamydia in American English
(kləˈmɪdiə)
noun
a widespread, gonorrhealike venereal disease caused by a bacterium (Chlamydia trachomatis) that also causes trachoma, etc.