1. Of or relating to phlegm; phlegmy.
a. Having or suggesting a calm, sluggish temperament; unemotional or apathetic.
b. Archaic Having phlegm as the dominant humor in terms of medieval physiology.
[Middle English fleumatik, from Old French fleumatique, from Late Latin phlegmaticus, full of phlegm, from Greek phlegmatikos, from phlegma, phlegmat-, heat, the humor phlegm, from phlegein, to burn; see bhel-1 in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.