Crossword Genius

Three climbing egg on a communist riled up (9)

Ross

I believe the answer is:

triggered

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

'riled up' is the definition.
The definition and answer can be both to do with contact as well as being past participle verbs.
Maybe you can see a link between them that I can't see?

'three climbing egg on a communist' is the wordplay.
'three' becomes 'tri' (prefix meaning 'three').
'climbing' says the letters should be written in reverse (in a down clue, letters climb up).
'on' means one lot of letters go next to another.
'a communist' becomes 'red' (red can informally mean communist).
'egg' backwards is 'gge'.
'tri'+'gge'+'red'='TRIGGERED'

Can you help me to learn more?

(Other definitions for triggered that I've seen before include "Caused (something) to happen" , "Set off" , "were let off" , "gets fired" .)

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