Bones smell, with heat rising (6)
I believe the answer is:
'bones' is the definition.
(I've seen this before)
'smell with heat rising' is the wordplay.
'smell' becomes 'hum' (something with a bad smell is 'humming').
'with' is a charade indicator (letters next to each other).
'heat' becomes 'ire' (I've seen this before).
'rising' says the letters should be written in reverse (going up in a down clue).
'ire' back-to-front is 'eri'.
(Other definitions for humeri that I've seen before include "Bones in upper arm from shoulder to elbow" , "Components of arms" , "Bones form shoulder to elbow" , "Upper-arm bones" , "Bones from shoulder to elbow, in Latin plural" .)