From nidor (“the unpleasant smell of some cooked animal substances”) + -ous, or from Medieval Latin nidorosus.
nidorous (comparative more nidorous, superlative most nidorous)
- (literary) Emitting a strong, unpleasant odor, especially one like that of cooking fat or similar greasy substances.
2002, Jamie O'Neill, chapter 10, in At Swim, Two Boys, →ISBN, page 240:
That old man's niderous whispered breath had entered into MacMurrough's heart an insufflation of—of what, exactly?
Emitting the odor or taste of roasted meat, especially rotten meat