Flatter, n.
1. One who, or that which, makes flat or flattens.
2. (Metal Working) (a) A flat-faced fulling hammer. (b) A drawplate with a narrow, rectangular orifice, for drawing flat strips, as watch springs, etc.
2 other Webster entries under this spelling
Flatter, v. t. [imp. & p. p. Flattered; p. pr. & vb. n. Flattering.]
1. To treat with praise or blandishments; to gratify or attempt to gratify the self-love or vanity of, esp. by artful and interested commendation or attentions; to blandish; to cajole; to wheedle. When I tell him he hates flatterers, He says he does, being then most flattered. Shak. A man that flattereth his neighbor, spreadeth a net for his feet. Prov. xxix. 5. Others he flattered by asking their advice. Prescott.
2. To raise hopes in; to encourage or favorable, but sometimes unfounded or deceitful, representations.
3. To portray too favorably; to give a too favorable idea of; as, his portrait flatters him.
Flatter, v. i.
To use flattery or insincere praise. If it may stand him more in stead to lie, Say and unsay, feign, flatter, or adjure. Milton.
Shades of meaning
Fernald has no entry of its own for flatter; he lists it under caress.
He lists it without comment; the entries above explain its neighbors.