Test the patience of a good man at a meeting (5)
I believe the answer is:
tryst
'a meeting' is the definition.
(I know that tryst is a type of appointment)
'test the patience of a good man' is the wordplay.
I cannot really see how this works, but
'test' could be 'try' (synonyms) and 'try' is located in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is located in the answer.
'good man' could be 's' and 's' is located in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'at' acts as a link.
Can you help me to learn more?
(Other definitions for tryst that I've seen before include "where lovers meet" , "private meeting" , "meeting-place" , "Lovers' assignation" , "Lovers' appointment" .)