Definition from Wiktionary, the free dictionary
laughing (plural laughings)
- The action of the verb to laugh.
- Present participle of laugh.
Usage notes 
As with other present participles, laughing can be used as an adjective:
- The Laughing Cavalier
- laughing hyena
Likewise, as with other gerunds, laughing can be used as a verbal noun:
- Laughing could be heard all the way from the back of the room!