Proceed into snug when darkness has fallen (7)
I believe the answer is:
tonight
'darkness has fallen' is the definition.
I can't judge whether this defines the answer.
'proceed into snug' is the wordplay.
'proceed' becomes 'on' (as imperatives both can mean 'go forward').
'into' is an insertion indicator.
'snug' becomes 'tight' (similar in meaning).
'on' placed inside 'tight' is 'TONIGHT'.
'when' acts as a link.
Can you help me to learn more?
(Other definitions for tonight that I've seen before include "later in the day" , "Hotting up for after sundown" , ""Not ____, Josephine!"" , "Dark time ahead" , "late in the day" .)