Crossword Genius

Charge then drop back, dispersed by this? (4,3)


I believe the answer is:

tear gas

I'm a little stuck... Click here to teach me more about this clue!

'dispersed by this?' is the definition.
The definition suggests a singular noun which matches the answer.

'charge then drop back' is the wordplay.
'charge then' becomes 'tear' (synonyms. I am not sure about the 'then' bit.).
'drop' becomes 'sag' (sagging is a kind of dropping).
'back' shows that the letters should be reversed in order.
'sag' backwards is 'gas'.

Can you help me to learn more?

(Other definitions for tear gas that I've seen before include "'It can be used to disperse crowds (4,3)'" , "Crowd disperser" , "Irritating stuff" , "Police weapon" , "Riot-control weapon" .)

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