Expressions (phrases, clauses, etc.), Ichidan verb, Intransitive verb
to become unrestrained and go to excess; to lose all restraint; to lose one's tension and become relaxed; to let go; to become disorderly; to be scattered; to lose one's self-control
Also written たがが外れる【たががはずれる】、箍が外れる【たががはずれる】