Terrapins when swimming breathe through the skin (9)
I believe the answer is:
transpire
'skin' is the definition.
The answer and definition can be both related to bodily activities as well as being verbs in their base form.
Perhaps they are linked in a way I don't understand?
'terrapins when swimming breathe through the' is the wordplay.
'terrapins' can be anagrammed to 'TRANSPIRE'.
Though, I am unsure how this is indicated.
Can you help me to learn more?
(Other definitions for transpire that I've seen before include "Terrapins (anag)" , "exhale" , "Come to pass" , "Happen[s]" , "Become known about terrapins" .)