Webster’s Revised Unabridged Dictionary · 1913
Grimace
Gri·mace′ (grĭ·mās′), n. [F., prob. of Teutonic origin; cf. AS. grīma mask, specter, Icel. grīma mask, hood, perh. akin to E. grin.] A distortion of the countenance, whether habitual, from affectation, or momentary and occasional, to express some feeling, as contempt, disapprobation, complacency, etc.; a smirk; a made-up face. [1913 Webster]
Moving his face into such a hideous grimace, that every feature of it appeared under a different distortion. Addison. [1913 Webster]
☞ "Half the French words used affectedly by Melantha in Dryden's "Marriage a-la-Mode," as innovations in our language, are now in common use: chagrin, double-entendre, éclaircissement, embarras, équivoque, foible, grimace, naïvete, ridicule. All these words, which she learns by heart to use occasionally, are now in common use." I. Disraeli. [1913 Webster]
Gri·mace′, v. i. To make grimaces; to distort one's face; to make faces. H. Martineau.