1. irresponsible
I am alarmed by your irresponsible attitude.
I want to find out the source of this irresponsible rumor.
It is irresponsible of you to break your promise.
She charged me with being irresponsible.
It would be irresponsible to ignore these warnings.
You can't trust him with anything. He's very irresponsible.
He was lazy and irresponsible. Thus, he was told to leave the company.
How irresponsible!
So, it seems you've been a bit irresponsible. / I don't understand why he's being so irresponsible.
He's fully aware of his irresponsible behaviour.
I don't understand why he's being so irresponsible. / 2. It's time for me to stop bein' so irresponsible. / 3. I can't believe you're so... irresponsible.
An irresponsible person is a person who makes vague promises, then breaks his word, blames it on circumstances and expects other people to forgive it.
She had never broken a law or done anything irresponsible.
Don’t go out with Vanessa – she’s too irresponsible.
It was very irresponsible of her to let the cat out while the fireworks were going on.