v.tr. 1 compliment unduly; overpraise, esp. for gain or advantage. 2 (usu. refl.; usu. foll. by that + clause) please, congratulate, or delude (oneself etc.) (I flatter myself that I can sing). 3 a (of a colour, a style, etc.) make (a person) appear to the best advantage (that blouse flatters you). b (esp. of a portrait, a painter, etc.) represent too favourably. 4 gratify the vanity of; make (a person) feel honoured. 5 inspire (a person) with hope, esp. unduly (was flattered into thinking himself invulnerable). 6 please or gratify (the ear, the eye, etc.). flattering unction a salve that one administers to one's own conscience or self-esteem (Shakesp. esp. Hamlet III. iv. 136). flatterer n. flattering adj. flatteringly adv.
[ ME, perh. rel. to OF flater to smooth ]