illegitimate

fatherless, motherless

nameless

adopted, orphaned

bad, evil, immoral, shameful, sinful, unethical, wicked, wrong

blamable, blameworthy, censurable, reprehensible

banned, barred, contraband, criminalized, disallowed, discouraged, forbidden, interdicted, outlawed, prohibited, proscribed

adulterine, bootleg, unauthorized, unlicensed, unsanctioned

under-the-counter, under-the-table

corrupt, unprincipled, unscrupulous, villainous

eristic (also eristical), misleading, sophistic (or sophistical), specious

half-baked, ill-advised, misguided, unconsidered, unreasoned

inconsistent

absurd, asinine, foolish, meaningless, nonsensical, preposterous, reasonless, senseless, silly

Kafkaesque, odd, peculiar, strange, surreal, unusual, weird

insane, mad, nutty, wacky (also whacky)

disordered, disorganized, rambling, random

unconvincing

inexplicable, unaccountable, unexplainable