Merriam-Webster Collegiate Dictionary - laugh

 I. verb  Etymology: Middle English, from Old English hliehhan; akin to Old High German lachen to ~  Date: before 12th century  intransitive verb  1.  a. to show emotion (as mirth, joy, or scorn) with a chuckle or explosive vocal sound  b. to find amusement or pleasure in something ~ed at his own clumsiness  c. to become amused or derisive a very skeptical public ~ed at our early efforts — Graenum Berger  2.  a. to produce the sound or appearance of ~ter a ~ing brook  b. to be of a kind that inspires joy  transitive verb  1. to influence or move by ~ter ~ed the bad singer off the stage  2. to utter with a ~  • ~ingly adverb  II. noun  Date: 1690  1. the act of ~ing  2.  a. a cause for derision or merriment ; joke  b. an expression of scorn or mockery ; jeer  3. plural diversion, sport play baseball just for ~s