- Demeanor is defined as the way a person behaves.
An example of demeanor is someone being peaceful.
This woman has a peaceful demeanor.
demeanor definition by Webster's New World
Origin: Middle English demenure ; from demenen, to rule, govern oneself, behave ; from Old French demener, to lead ; from de- (L de), from plush mener, to lead ; from Late Latin minare, to drive (cattle) ; from Classical Latin minari, to threaten: see menace
demeanor definition by American Heritage Dictionary