In action it resembles saltpetre (5)

I believe the answer is:

nitre

'saltpetre' is the definition.
('nitre' can be a synonym of 'saltpetre')

'in action it resembles' is the wordplay.
'in' says the answer is hidden in the clue.
'NITRE' is hidden in the letters of 'action it resembles'.

(Other definitions for nitre that I've seen before include "Mineral used in gunpowder" , "Inert (anag) - saltpetre" , "Sodium nitrate" , "constituent of gunpowder" , "explosive ingredient" .)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.