fetoro

There is no -or- suffix in Esperanto, so nothing peels off this word. The official suffix list runs -ad-, -aĵ-, -an-, -ar-, -ebl-, -ec-, -eg-, -ej-, -em-, -end-, -er-, -estr-, -et-, -id-, -ig-, -iĝ-, -il-, -in-, -ind-, -ing-, -ism-, -ist-, -obl-, -on-, -op-, -uj-, -ul- and -um-, and -or- is not on it and never was. So fet- plus -or- is not a reading that was ever available. Fetor- is one root.

It is a whole class, not a one-off. The -oro ending you keep meeting is just the Latin ending riding in on the borrowed word: doloro, koloro, honoro, vaporo, humoro, odoro. Every one of them is a single root, and a learner who starts stripping -or- will produce dol-, kol- and hon-, none of which mean anything. The rule that saves you is the one from kombini: if a word came in from the international vocabulary, assume it is one root until a dictionary says otherwise.

The strength fence. Odoro is neutral - a smell, which might be roses. Fetoro is not neutral and never was: it is a stink strong enough to be a problem, the smell of something putranta. The adjective is fetora and the verb fetori, to reek. If you want the neutral verb, that is flari for the nose doing the work and odori for the thing giving off the smell.