Definition of "irresponsible"

irresponsible

/ˌɪɹ.ɪˈspɒn.sə.bəl/

adjective
comparative more irresponsible, superlative most irresponsible
1. (now rare) Not responsible; exempt from legal responsibility, not to be held accountable.
  Quotations
  They left the crown what, in the eye and estimation of law, it had ever been, perfectly irresponsible.
  1790, Edmund Burke, Reflections on the Revolution in France, Oxford, published 2009, page 28
2. Lacking a sense of responsibility; performed or acting as though without responsibility; negligent.
noun
plural irresponsibles
1. Someone who is not responsible.