n.
A sterile liquid containing proteins extracted from cultures of tubercle bacilli and used in tests for tuberculosis.
[Latin tūberculum, tubercle; see tubercle + -IN.]
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.