n. (Abbr. STD)
Any of various diseases, including chancroid, chlamydia, gonorrhea, and syphilis, that are usually contracted through sexual intercourse or other intimate sexual contact.
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.