Prepared to admit (4)
I believe the answer is:
open
This might be a double definition.
'prepared' is the first definition.
Both the definition and answer are adjectives. Perhaps you can see a link between them that I can't see?
'admit' is the second definition.
The definition and answer can be both to do with social activities as well as being verbs in their base form.
Maybe there's an association between them I don't understand?
'to' is the link.
Can you help me to learn more?
(Other definitions for open that I've seen before include "'Frank, not secret (4)'" , "hardly high-security" , "ready to entertain new ideas" , "Honest - frank" , "Not enclosed" .)