Girl's fair-trade candle regularly used (5)

I believe the answer is:

irene

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'girl's' is the definition.
(I've seen this before)

I cannot understand how the rest of the clue works.

(Other definitions for irene that I've seen before include "Female name" , "Girl's name (meaning Peace)" , "Girl of peace" , "- - Worth, actress" , "In Greek mythology, the goddess of peace" .)

I've seen this clue in The Independent.

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