Food colouring — girl to accept first time (7)
I believe the answer is:
annatto
'food colouring' is the definition.
(I've seen this before)
'girl to accept first time' is the wordplay.
'girl' becomes 'anna' ().
'accept' means one lot of letters goes inside another.
'first time' becomes 't' (ast letter of 'time').
'to' going around 't' is 'tto'.
'anna'+'tto'='ANNATTO'
(Other definitions for annatto that I've seen before include "food colouring" , "Food dye from red pulp of tropical fruit" , "tree" , "Food colourant" , "Colouring matter" .)