Snicker1. (v. i.) To laugh slyly; to laugh in one's sleeve.
2. (v. i.) To laugh with audible catches of voice, as when persons attempt to suppress loud laughter.
3. (n.) A half suppressed, broken laugh.
Thesaurus Entries
Homeric laughter, be in stitches, belly laugh, boff, boffola, break up, burst into laughter, burst of laughter, burst out, burst out laughing, burst with laughter, bust a gut, cachinnate, cachinnation, cackle, chortle, chuckle, convulsion, crow, fit of laughter, fleer, gales of laughter, giggle, go into convulsions, guffaw, ha-ha, hearty laugh, hee-haw, hee-hee, hilarity, ho-ho, horselaugh, jeer at, laugh, laugh at, laugh it up, laugh outright, laughing, laughter, leer, mock, nearly die laughing, outburst of laughter, peal of laughter, risibility, roar, roar of laughter, roar with laughter, sardonic grin, scorn, scornful laugh, shake like jelly, shake with laughter, shout, shout of laughter, shriek, smirk, sneer, snigger, sniggle, snort, split, split with laughter, tee-hee, titter, yuck, yuk-yuk