Crossword Genius

It's a long time since he brought you any sleep! (7)

Ross

I believe the answer is:

sandman

I'm a little stuck... Click here to teach me more about this clue!

'long time since he brought you any sleep' is the definition.
The definition suggests a singular noun which matches the answer. I also know that 'sleep' relates to this answer.

'it's a' is the wordplay.
'it's' becomes 'sandm' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'a' becomes 'an'.
'sandm'+'an'='SANDMAN'

Can you help me to learn more?

(Other definitions for sandman that I've seen before include "Imaginary person who causes children to sleep" , "Sender to sleep of children" , "sleep-inducing agent" , "Fairy who puts children to sleep" , "Children's bedtime fairy" .)

I've seen this clue in the Evening Standard.
Want a hint initially instead of a full solution? Install my app