Lockkeeper catching something cold and black in a net (5,4)
I believe the answer is:
alice band
'lockkeeper' is the definition.
(something which keeps locks of hair in place)
'something cold and black in a net' is the wordplay.
'something cold' becomes 'ice'.
'and' says to put letters next to each other.
'black' becomes 'b' (as in pencil classifications).
'in' is an insertion indicator.
'net' becomes 'land' (both can mean to secure or obtain).
'ice'+'b'='iceb'
'a'+'land'='aland'
'iceb' placed into 'aland' is 'ALICE BAND'.
'catching' acts as a link.
(Other definitions for alice band that I've seen before include "this on girl's head" , "overhead arch" , "one's found in hair" , "It's worn to hold back the hair" , "Lock keeper" .)