Adjective unconventional has 3 senses
- unconventional - not conforming to accepted rules or standards; "her unconventional dress and hair style"
Antonyms:  conventional, accepted, received, customary, stodgy, stuffy, formulaic
 - unconventional - not conventional or conformist; "unconventional life styles"
Antonyms:  accepted, received, customary, stodgy, stuffy, formulaic, conventional, button-down, buttoned-down, conservative, square, straight, stereotyped, stereotypic, stereotypical, unimaginative, white-bread
 - improper, unconventional, unlawful - not conforming to legality, moral law, or social convention; "an unconventional marriage"; "improper banking practices"
Antonym:  regular (indirect, via irregular)
 
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