Raise front of shelf in luggage compartment (5)
I believe the answer is:
boost
'raise' is the definition.
(I know that boost is a kind of raise)
'front of shelf in luggage compartment' is the wordplay.
'front of' says to take the initial letters (the letter at the front of the word).
'in' indicates putting letters inside.
'luggage compartment' becomes 'boot' (synonyms).
The initial letter of 'shelf' is 's'.
's' inserted inside 'boot' is 'BOOST'.
(Other definitions for boost that I've seen before include "Improve - pick-me-up" , "Increase (strength or morale)" , "Give more impetus to" , "Help to increase" , "Raise" .)