Do you think you know people? You may have to review your accounts, it is unlikely that you have ever heard the term "phlegm". As if you are smiling? Yes, it is true, the derivation here is from the word (phlegm), which is the mucous fluid, which is produced by the respiratory system, to clean itself. If you want to know the meaning of this term, which was mentioned by the famous Greek philosopher (Hippocrates), in his classification of human figures, then continue to read with us, you may be a "phlegm" person and you do not know!