unconventional
un-con-ven-tion-al
adjective
Not conforming to what is generally accepted, traditional, or usual.
"Her unconventional approach to art was refreshing."
Thesaurus
Synonyms: improper, unlawful, irregular, quirky, freakish, freaky, off-the-wall, devil-may-care, raffish, offbeat, bizarre, spaced-out
Antonyms: conventional