Most of the journey is free (3)
I believe the answer is:
rid
'is free' is the definition.
('rid' can be similar in meaning to 'free')
'most of the journey' is the wordplay.
'most of' means to remove the last letter.
'the journey' becomes 'ride' (ride is a kind of journey).
'ride' with its last letter taken off is 'RID'.
(Other definitions for rid that I've seen before include "Free, disencumber" , "Lose, shake off" , "Clear, remove" , "Free (someone of something unwanted)" , "Free from something unpleasant" .)