Crossword Genius

Female I rebuke is impervious to a tongue (9)

Ross

I believe the answer is:

fireproof

'impervious to a tongue' is the definition.
(tongue can mean a flame)

'female i rebuke' is the wordplay.
'female' becomes 'f' (abbreviation).
'rebuke' becomes 'reproof' (synonyms).
'f'+'i'+'reproof'='FIREPROOF'

'is' acts as a link.

(Other definitions for fireproof that I've seen before include "Incombustible" , "Able to withstand great heat" , "Unlikely to flare up" , "safe?" , "unlikely to go up" .)

I've seen this clue in The Guardian.
Want a hint initially instead of a full solution? Install my app