Circular enclosure with free access (4)
I believe the answer is:
open
'free access' is the definition.
'open' can be an answer for 'free' (I've seen this before). I'm not certain of the 'access' bit.
'circular enclosure' is the wordplay.
'circular' becomes 'o' (I've seen this in other clues).
'enclosure' becomes 'pen' (pen is a kind of enclosure).
'o'+'pen'='OPEN'
'with' acts as a link.
Can you help me to learn more?
(Other definitions for open that I've seen before include "Eager to receive" , "Candid - ready for business" , "This championship includes both professional and amateur golfers" , "such a verdict?" , "ready to entertain new ideas" .)