Crossword Genius

Allow access to a circular enclosure (4)

Ross

I believe the answer is:

open

I'm a little stuck... Click here to teach me more about this clue!

'allow access' is the definition.
I can't tell whether this defines the answer.

'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'

'to a' acts as a link.

Can you help me to learn more?

(Other definitions for open that I've seen before include "Sports contest" , "gaping" , "unsealed" , "Public" , "Allowing access" .)

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