Relaxes, as it is, after school (4)
I believe the answer is:
sits
'relaxes' is the definition.
Although both the answer and definition are verbs in their -s form, I cannot understand how they can define each other.
'it is after school' is the wordplay.
I cannot quite see how this works, but
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is found in the answer.
'is' is within the answer.
'school' could be 's' and 's' is found within the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'as' acts as a link.
Can you help me to learn more?
(Other definitions for sits that I've seen before include "Poses for a painter" , "Perches" , "Takes a seat for the painter" , "Takes a chair" , "Takes an exam" .)