Crossword Genius

Promise to use bad language (5)

Ross

I believe the answer is:

swear

This clue is a double definition.

'promise' is the first definition.
(thesaurus)

'use bad language' is the second definition.
(I've seen this before)

'to' acts as a link.

(Other definitions for swear that I've seen before include "Affirm" , "Vow; blaspheme" , "Promise on oath" , "Use bad language" , "Emit oath or take vow" .)

I've seen this clue in The Independent.
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