Sneer, v. i. [imp. & p. p. Sneered; p. pr. & vb. n. Sneering.]
Etymology: [OE. sneren, Dan. sn to snarl or grin (like a dog); cf. Prov. E. sneer to grin, sner to snort, snert to sneer at. See Snore, v. i.]

This face is called Scorn. The day birds are mocking the owl.
Scorn, Eduardus Jacobus, after 1698. Art Institute of Chicago.1. To show contempt by turning up the nose, or by a particular facial expression.
2. To inssinuate contempt by a covert expression; to speak derisively. I could be content to be a little sneared at. Pope.
3. To show mirth awkwardly. [R.] Tatler.
Syn. -- To scoff; gibe; jeer. -- Sneer, Scoff, Jeer. The verb to sneer implies to cast contempt indirectly or by covert expressions. To jeer is stronger, and denotes the use of several sarcastic reflections. To scoff is stronger still, implying the use of insolent mockery and derision. And sneers as learnedly as they, Like females o'er their morning tea. Swift. Midas, exposed to all their jeers, Had lost his art, and kept his ears. Swift. The fop, with learning at defiance, Scoffs at the pedant and science. Gay.
2 other Webster entries under this spelling
Sneer, v. t.
1. To utter with a grimace or contemptuous expression; to utter with a sneer; to say sneeringly; as, to sneer fulsome lies at a person. Congreve. "A ship of fools," he sneered. Tennyson.
2. To treat with sneers; to affect or move by sneers. Nor sneered nor bribed from virtue into shame. Savage.
Sneer, n.
1. The act of sneering.
2. A smile, grin, or contortion of the face, indicative of contempt; an indirect expression or insinuation of contempt. "Who can refute a sneer" Raley.
Shades of meaning
A sneer may be simply a contemptuous facial contortion, or it may be some brief satirical utterance that throws a contemptuous side-light on what it attacks without attempting to prove or disprove; a depreciatory implication may be given in a sneer such as could only be answered by elaborate argument or proof, which would seem to give the attack undue importance:
Who can refute a sneer?
PALEY Moral Philosophy bk. v, ch. ix.
A fling is careless and commonly pettish; a taunt is intentionally insulting and provoking; the sneer is supercilious; the taunt is defiant. The jeer and gibe are uttered; the gibe is bitter, and often sly or covert; the jeer is rude and open. A scoff may be in act or word, and is commonly directed against that which claims honor, reverence, or worship. Compare banter.
Prepositions
Only an essentially vicious mind is capable of a sneer at virtue.