Skeletal pub in space (6)
I believe the answer is:
skinny
'skeletal' is the definition.
(thesaurus)
'pub in space' is the wordplay.
'pub' becomes 'inn' (an inn is a type of pub).
'in' is an insertion indicator.
'space' becomes 'sky' (I've seen this in other clues).
'inn' going into 'sky' is 'SKINNY'.
(Other definitions for skinny that I've seen before include "Euphemism for a caffe latte with skimmed (non-fat) milk" , "Scraggy, scrawny" , "far from stout!" , "stout? Certainly not!" , "Of person, very thin" .)