The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.
snicker
SYLLABICATION: snick·er
PRONUNCIATION: snkr
INTRANSITIVE VERB: Inflected forms: snick·ered, snick·er·ing, snick·ers
To utter a partly stifled laugh: “I have seen the eternal Footman hold my coat, and snicker” (T.S. Eliot).
NOUN: A snide, slightly stifled laugh.
ETYMOLOGY: Perhaps imitative.
OTHER FORMS: snicker·ing·ly ”ADVERB