More mature traveller grabs parking for day (5)
I believe the answer is:
riper
'more mature' is the definition.
('ripe' can be similar in meaning to 'mature')
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for riper that I've seen before include "Maturer" , "like a better mousetrap?" , "More harvestable" , "More ready to pick" , "More suitable for picking" .)