On which one perhaps sits to be in the sun (5)
I believe the answer is:
stool
'on which one perhaps sits' is the definition.
I can't tell whether this definition defines the answer.
'to be in the sun' is the wordplay.
'be in the' means one lot of letters goes inside another.
'sun' becomes 'sol' (Latin for 'sun').
'to' placed inside 'sol' is 'STOOL'.
Can you help me to learn more?
(Other definitions for stool that I've seen before include "Simple seat" , "Backless chair" , "item of furniture here" , "Small seat" , "Seat without a back" .)