unintentional
adj.done or happening by accident, not because you planned it. You use this to describe mistakes or surprises that you did not mean to cause.
adj.not done with purpose or intent; occurring without deliberate planning. Often used to qualify negative outcomes or errors to mitigate blame.
“I am sorry for the unintentional mistake on the report.”
“The comedian's joke caused some unintentional offense among the audience members who took it literally.”
“While the policy change was designed to improve efficiency, it had the unintentional consequence of alienating the company's most loyal long-term clients.”
Typically used attributively before a noun; often paired with words like 'mistake', 'harm', or 'consequence'.
“Engineers identified the unintentional opening of a vent valve and a loss of attitude control as the cause of the failure.”
“They often explained what happened, stressed that the offense was unintentional or used impersonal phrases such as " se me olvidó " (which roughly translates as "it slipped my mind").”
From un- + intentional.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.