Does all one can to get rid of undesirable elements (7)
I believe the answer is:
strains
'does' is the definition.
The answer and definition can be both related to bodily activities as well as being verbs in their -s form.
Maybe there's a link between them I don't understand?
'all one can to get rid of undesirable elements' is the wordplay.
I cannot quite see how this works, but
'one' could be 'i' (Roman numeral) and 'i' is located in the answer.
'elements' could be 'ns' (N is an example) and 'ns' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for strains that I've seen before include "Tries very hard" , "Melodies" , "Stresses and - -" .)