Family members making trips topless? (5)
I believe the answer is:
aunts
'family members' is the definition.
'trips topless?' is the wordplay.
'trips' becomes 'jaunts' ('jaunt' can be a synonym of 'trip').
'topless?' means to remove the first letter (I've seen 'topless' mean this).
'jaunts' with its first letter taken away is 'AUNTS'.
'making' is the link.
(Other definitions for aunts that I've seen before include "Elderly female relations" , "Parents' sisters" , "Relatives get a peculiar US tan" , "relatively speaking" , "Sally and others" .)