laughter

What it means

1. uncountableusuallyThe sound of laughing, produced by air so expelled; any similar sound.

   Their loud laughter betrayed their presence.

   1 more example

   There was some laughter, and Roddle was left free to expand his ideas on the periodic visits of cowboys to the town.

   1899, Stephen Crane, chapter 1, in Twelve O'Clock

2. uncountableusuallyA movement (usually involuntary) of the muscles of the laughing face, particularly of the lips, and of the whole body, with a peculiar expression of the eyes, indicating merriment, satisfaction or derision, and usually attended by a sonorous and interrupted expulsion of air from the lungs.

   Archly the maiden smiled, and with eyes overrunning with laughter.

   1858 October 16, Henry Wadsworth Longfellow, “The Courtship of Miles Standish”, in The Courtship of Miles Standish, and Other Poems, Boston, Mass.: Ticknor and Fields, →OCLC

   1 more example

   The act of laughter, which is caused by a sweet contraction of the muscles of the face, and a pleasant agitation of the vocal organs, is not merely, or totally within the jurisdiction of ourselves.

   1646, Thomas Browne, Pseudodoxia Epidemica: […], London: […] T[homas] H[arper] for Edward Dod, […], →OCLC

3. archaicuncountableusuallyA reason for merriment.

In a sentence

Their loud laughter betrayed their presence.

Where it comes from

1. Proto-Indo-European*klek-
2. Proto-Germanic*hlahtraz“laughter”
3. Old Englishhleahtor“laughter, jubilation, derision”
4. Middle Englishlaughter
5. Englishlaughter

From Middle English laughter, laghter, laȝter, from Old English hleahtor (“laughter, jubilation, derision”), from Proto-Germanic *hlahtraz (“laughter”), from Proto-Indo-European *klek-, *kleg- (“to shout”). Cognate with German Gelächter (“laughter, hilarity, merriment”), Danish and Norwegian latter (“laughter”), Icelandic hlátur (“laughter”). More at laugh.