Like a loyalist starting to travel on from Rouen (4)
I believe the answer is:
true
'like a loyalist starting' is the definition.
I can't judge whether this defines the answer.
'travel on from rouen' is the wordplay.
'travel' becomes 't' (this might be a standard abbreviation of which I'm unaware).
'from' indicates named letters should be taken away.
'rouen' with 'on' removed is 'rue'.
't'+'rue'='TRUE'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for true that I've seen before include "Bona fide" , "Genuine, actual" , "Real, actual" , "Dependable -- loyal" , "Agreeing with fact or reality" .)