Calendar girl can return (7)
I believe the answer is:
almanac
'calendar' is the definition.
(I've seen this before)
'girl can return' is the wordplay.
'girl' becomes 'alma' (girl's name).
'return' says the letters should be written backwards.
'can' reversed gives 'nac'.
'alma'+'nac'='ALMANAC'
(Other definitions for almanac that I've seen before include "Kind of year-book like Old Moore's" , "Sailor's or farmer's calendar" , "Calendar with detailed information" , "Annual publication providing information like Old Moore's" , "Annual publication containing information in a particular field" .)