This is the 13484th most frequent Turkish word.
koptu
"Koptu" means "broke off" or "detached" in English.
In this sentence, 'koptu' is used to describe a literal breaking or snapping of an object, in this case, a rope.
İp koptu.
The rope broke.
'Koptu' here figuratively expresses that something (the party) became very exciting or energetic.
Partide eğlence koptu.
The party turned lively.
This usage of 'koptu' indicates a figurative reaction to extreme laughter, suggesting that the individual was unable to control their emotions due to intense amusement.