sneer (v.) Look up sneer at Dictionary.com
1550s, "to snort" (of horses), perhaps from North Frisian sneere "to scorn," related to Old English fnæran "to snort, gnash one's teeth," of imitative origin (compare Danish snærre "to grin like a dog," Middle Dutch, Middle High German snarren "to rattle"). Meaning "to smile contemptuously" is from 1670s; sense of "to curl the upper lip in scorn" is attested from 1775. Related: Sneered; sneering. Sneer word is in E. Digby Baltzell (1987).
sneer (n.) Look up sneer at Dictionary.com
1707, from sneer (v.).