Reddish dye (5)
I believe the answer is:
henna
'reddish dye' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for henna that I've seen before include "Beauty aid" , "Hair/skin dye" , "Pigment used on skin" , "Reddish-brown hair-dye" , "(Shrub producing) reddish dyestuff" .)