Going by, has to join queen to be good enough (7,6)
I believe the answer is:
passing muster
'be good enough' is the definition.
I know nothing about this answer so I can't tell whether this works.
'going by has to join queen' is the wordplay.
'going by' becomes 'passing' ('pass' can be a synonym of 'go by').
'has to' becomes 'must' (I've seen this in another clue).
'join' means one lot of letters go next to another.
'queen' becomes 'ER' (abbreviation for Elizabeth Regina).
'passing'+'must'+'er'='PASSING MUSTER'
'to' is the link.
Can you help me to learn more?
(Other definitions for passing muster that I've seen before include "being good enough" , "Making the grade" .)