See snicker in Webster's New World Roget's A-Z Thesaurus II
verb
To laugh in a stifled way:
giggle, snigger, titter. See laughterTo smile or laugh scornfully or derisively:
fleer, sneer, snigger. Idiom: curl one's lip. See express, laughter, respect
noun
A stifled laugh:
giggle, snigger, titter. See laughterA facial expression or laugh conveying scorn or derision:
fleer, sneer, snigger. See express, laughter, respect
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