Not so anxious since replacement's arrived? (8)
I believe the answer is:
relieved
'arrived?' is the definition.
The answer and definition can be both to do with social activities as well as being past participle verbs.
Maybe they are linked in a way I don't understand?
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for relieved that I've seen before include "siege is broken?" , "'Alleviated, lightened (8)'" , "Grateful" , "Freed by a substitute? - that relaxed the tension" , "Not so anxious - replacement has arrived" .)