There's agreement after I'm in collision (6)
I believe the answer is:
impact
'collision' is the definition.
(I've seen this in another clue)
'there's agreement after i'm' is the wordplay.
'there's agreement' becomes 'pact' (I can't justify this - if you can you should give a lot more credence to this answer).
'after' means one lot of letters go next to another.
'pact' put after 'im' is 'IMPACT'.
'in' is the link.
Can you help me to learn more?
(Other definitions for impact that I've seen before include "Forcible contact between two things" , "The force of one body against another" , "Force exerted by collision" , "The force fo violent strike" , "Repercussions" .)