Star that's hit Tanner? (7)
I believe the answer is:
sunlamp
'tanner?' is the definition.
(something which gives someone a tan)
'star that's hit' is the wordplay.
'star' becomes 'sun' (the Sun is a star).
'that's hit' becomes 'lamp' (lamp can mean to hit someone).
'sun'+'lamp'='SUNLAMP'
(Other definitions for sunlamp that I've seen before include "Device used in artificial tanning" , "Tanner" , "Source of UV rays for cosmetic purposes" .)