Défoncer belong to the 1
st group. Défoncer is a common french verb.
Défoncer is conjugated the same way that verbs that end in :
-cer
Défoncer is conjugated with
auxiliary avoir.
Défoncer verb is
direct transitive.
French verb défoncer can be conjugated in the reflexive form:
Se défoncer
Défoncer verb is a direct transitive verb, so passive voice can be used.