Relations to make trips, heading off (5)
I believe the answer is:
aunts
'relations' is the definition.
(aunt is a kind of relation)
'trips heading off' is the wordplay.
'trips' becomes 'jaunts' ('jaunt' can be a synonym of 'trip').
'heading off' means to remove the first letter.
'jaunts' with its initial letter removed is 'AUNTS'.
'to make' is the link.
(Other definitions for aunts that I've seen before include "Relatives get a peculiar US tan" , "Sally and others" , "Relatives get bad US tan" , "Female relatives, usually older" , "Parents' sisters" .)