accidental
ac·ci·den·tal
/ˌæksəˈdɛntl̩/ adj
: happening in a way that is not planned or intended : happening by accident
an accidental discovery of oil
The timing of the announcement was purely accidental.
: happening as an accident
an accidental shooting
The death was ruled accidental.
ac·ci·den·tal·ly /ˌæksəˈdɛntl̩i/ adv
He accidentally deleted the file.
The lock prevents the gate from opening accidentally.
Did it happen accidentally [=by accident] or intentionally?
He bumped into her accidentally on purpose. [=he bumped into her on purpose but he tried to make it appear to be an accident]
