What she and he do in verse? (5)
I believe the answer is:
rhyme
'verse?' is the definition.
(a rhyme is a piece of verse)
'what she and he do' is the wordplay.
I cannot quite see how this works, but
'he' could be 'hy' and 'hy' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
'in' acts as a link.
Can you help me to learn more?
(Other definitions for rhyme that I've seen before include "Without reason or . . . . . - makes no sense" , "Correspondence in the sounds of two or more words" , "'Moon' and 'June' do" , "Bit of poetry" , "word pattern" .)