Sit out with a girl in gauzy fabric (6)
I believe the answer is:
tissue
'gauzy fabric' is the definition.
(I've seen this before)
'sit out with a girl' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'with' means one lot of letters go next to another.
'a girl' becomes 'sue' (girl's name).
'sit' with letters rearranged gives 'tis'.
'tis'+'sue'='TISSUE'
'in' acts as a link.
(Other definitions for tissue that I've seen before include "Cells sharing a function" , "Basic structural element of an animal or plant" , "Jewish religious leader" , "Absorbent paper, used as handkerchief, say" , "Paper hankie" .)