wilful
Pronunciation: /ˈwɪlfʊl, -f(ə)l/
(US also willful)
adjective

Spelling help
Remember that wilful is spelled with one l in the middle (the spelling willful is American).

Spelling rule
If a word ends in a double l, drop the last l when adding endings which begin with a consonant (here, will plus -ful): wilful.