On the way (2,5)
'on the way' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for en route that I've seen before include "In transit (French)" , "March" , "On the way - in France" , "While travelling" , "As part of a journey" .)
'on the way' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for along that I've seen before include "For the length of" , "Forward - in a line" , "Sea monster, opposite Charybdis" , "Moving in a constant direction on (something)" , "Lengthwise" .)