Антонимом being above board

dishonestly shadily

dishonest shady deceitful duplicitous crooked fraudulent underhand deceptive treacherous unscrupulous devious tricky false guileful shifty cunning crafty untrustworthy wily sneaky unprincipled dishonorable dishonourable underhanded insincere slippery dodgy lying unethical bent designing perfidious corrupt disreputable sharp unfair dirty untruthful cheating illegal misleading deceiving traitorous subtle shonky mendacious criminal immoral rogue fast knavish unlawful unctuous sneaking swindling unjust villainous recreant defrauding rascally amoral slim roguish truthless malfeasant hoodwinking elusive sinister untrusted Janus-faced double-faced hollow-hearted false-hearted

illegal illegitimate illicit lawless unlawful wrongful criminal back-alley banned black-market contraband disallowed forbidden invalid outlawed unacceptable underage wrong

forbidden banned barred impermissible inadmissible interdicted prohibited proscribed verboten illegitimate unacceptable unsuitable wrong

being a crybaby being alone being as being a straight shooter being aware of being busy being above being able to being able being be infuriated be in front of