Religious woman starts the Canticle of Simeon (3)
I believe the answer is:
nun
'religious woman' is the definition.
(woman who has taken religious vows)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for nun that I've seen before include "One in holy order" , "Convent dweller" , "One who's taken vows" , "She's a member of a religious community" , "Member of convent" .)