de·mean 1 (dĭ-mēn') tr.v.
de·meaned, de·mean·ing, de·means To conduct or behave (oneself) in a particular manner: demeaned themselves well in class.
[Middle English demeinen, to govern, from Old French demener : de-, de- + mener, to conduct (from Latin mināre, to drive (animals), from minārī, to threaten, from minae, threats; see men-2 in Indo-European roots).]