Irresponsible means not taking proper care of duties. Irresponsible behaviour, grossly irresponsible, an irresponsible decision.
It is a real accusation rather than a mild one: calling a decision irresponsible says the person knew the risk and disregarded it. It attaches to driving, to spending and to public statements. Note that irresponsible is not the same as unaccountable, though the words look related — an irresponsible person neglects duties, and an unaccountable one simply cannot be called to answer for them.
1adjectiveirresponsibleNot taking proper care of duties.
“It was irresponsible of him to leave the children alone in the house.”
irresponsible is a quality of neglect.
Latin
responsus
Old French
responsable
Middle French
responsable
English
responsible
English, today
irresponsible
From ir- + responsible. responsible comes from Middle French responsable, from Old French responsable, responsible, formed from the root of Latin responsus, from respondeō. The spelling of the English word is taken from the Old French variant responsible. by surface analysis, response + -ible.
Etymology from Wiktionary, CC BY-SA