Seed a door-opening word (6)
I believe the answer is:
sesame
This could be a double definition.
'seed a door' is the first definition.
'sesame' can be an answer for 'seed' (I've seen this before). I'm not sure about the 'a door' bit.
'opening word' is the second definition.
(I've seen this in another clue)
Can you help me to learn more?
(Other definitions for sesame that I've seen before include "Source of seed and oil" , "Plant grown for its seeds" , "A seed; a TV Street" , "'Open - - !' (Ali Baba)" , "Oil-rich seed plant" .)