PHLEgmatic definition
Full Definition of PHLEGMATIC. 1. : resembling, consisting of, or producing the humor phlegm(see phlegm). 2. : having or showing a slow and stolid temperament. â phlegÂ·matÂ·iÂ·calÂ·ly \-ti-k(É-)lÄ\ adverb. See phlegmatic defined for English-language learners.