It's aggressive to stuff falcon onto train (15)
I believe the answer is:
confrontational
'it's aggressive' is the definition.
I can't tell whether this defines the answer.
'stuff falcon onto train' is the wordplay.
'stuff' indicates anagramming the letters (I've seen 'stuffed' mean this).
'falcon'+'onto'+'train'='falconontotrain'
'falconontotrain' is an anagram of 'CONFRONTATIONAL'.
'to' is the link.
Can you help me to learn more?
(Other definitions for confrontational that I've seen before include "wanting to encourage hostility" , "Aggressively hostile" , "Openly hostile" , "Dealing hostilely with others" .)