to please or gratify by compliments or attentions: I was flattered by their invitation.
7.
to feel satisfaction with (oneself), especially with reference to an accomplishment, act, or occasion: He flattered himself that the dinner had gone well.
8.
to beguile with hope; encourage prematurely, falsely, etc.
Origin: 1175–1225; Middle English flat(t)eren to float, flutter, fawn upon, Old English floterian to float, flutter; for sense development, compare flicker1, Old Norse flathra; reinforced by Old French flatter to flatter, literally, to stroke, caress (probably < Frankish *flat-flat1)
early 13c., from O.Fr. flater "to flatter," originally "stroke with the hand, caress," from Frank. *flat "palm, flat of the hand" (see flat (adj.)). Related: Flattered; flattering.