Learner's definition of IRRESPONSIBLE
[more irresponsible; most irresponsible]
: not having or showing maturity or good judgment : not responsible
He's too irresponsible to keep a job for more than a week.
She made irresponsible comments that helped cause the riot.
It would be irresponsible to ignore the threats.
— irresponsibly/ˌirɪˈspɑːnsəbli/adverb,[more irresponsibly; most irresponsibly]