Other forms: laughing, laughs, laughed
To laugh is to make the sound of amusement. Laugh out loud, make her laugh, laughing at nothing.
The gh is silent and the word rhymes with staff in Britain. Laugh at somebody is mocking and laugh with them is not, which is the whole difference. Laugh off means to dismiss something by treating it as funny. Note the last laugh, meaning eventual vindication; laugh up your sleeve; and that laughing is contagious and measurably more likely in company than alone.
1verblaughTo make the sound of amusement.
“The children laughed at the clown's funny face.”
laugh is a sound of amusement.
Old English hlaehhan is imitative and Germanic — the same origin as the German lachen. Almost every language builds its laughing word out of the sound, which is why they resemble each other without being related.
Middle English
laughen
English, today
laugh
Built from
From Middle English laughen. From Middle English laughen, laghen, from (Anglian) Old English hlæhhan, hlehhan, (West Saxon) hliehhan, from Proto-West Germanic hlahhjan, from Proto-Germanic hlahjaną. 2
Etymology from Wiktionary, CC BY-SA