Gerund used as an uncountable noun meaning the act or process of celebrating.
There was exuberant celebrating after the election results were announced.
Il y a eu une célébration exubérante après l'annonce des résultats de l'élection.
celebratinggerund / present participle Present-participle adjective used attributively (e.g., "celebrating crowd").
The celebrating fans poured into the streets waving flags.
Les fans célébrant la victoire ont envahi les rues en agitant des drapeaux.