Queen Street, at an earlier time (4)
I believe the answer is:
erst
'an earlier time' is the definition.
I can't tell whether this defines the answer.
'queen street' is the wordplay.
'queen' becomes 'ER' (abbreviation for Elizabeth Regina).
'street' becomes 'st' (abbreviation).
'er'+'st'='ERST'
'at' is the link.
Can you help me to learn more?
(Other definitions for erst that I've seen before include "Rest turned formerly" , "At first; formerly" , "in former times" , "in the past" .)