Visitor at night with mother welcomed by partners (7)
I believe the answer is:
sandman
'visitor at night' is the definition.
I can't judge whether this defines the answer.
'with mother welcomed by partners' is the wordplay.
'with' becomes 'and'.
'mother' becomes 'ma' (Ma is another word for mother or mum).
'welcomed by' means one lot of letters goes inside another (letters welcomed inside).
'partners' becomes 'sn' (South and North are partners in the game bridge).
'and'+'ma'='andma'
'andma' put into 'sn' is 'SANDMAN'.
Can you help me to learn more?
(Other definitions for sandman that I've seen before include "sleepy character?" , "One of the Beach Boys" , "Fairy who puts children to sleep" , "Sender to sleep of children" , "sleep-inducing agent" .)