unwilful
/ˌʌnˈwɪlfʊl, ˌʌnwɪˈfʊl/Definitions
1. adjective
Lacking intention or purpose; unintentional.
“The wilful damage caused by the teenagers was a result of their unwilful disregard for the property.”
2. adverb
In a manner that is unintentional or lacking intention.
“She laughed unwilfully at the silly joke.”