What a chest expander will never do? (6)
I believe the answer is:
exhale
'do?' is the definition.
The definition and answer can be both related to bodily activities as well as being verbs in their base form.
Maybe they are linked in a way I don't understand?
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for exhale that I've seen before include "Expel air from the lungs" , "Give out" , "send forth wind" , "Emit breath" , "expire" .)