A labyrinth has daughter dumbfounded (6)
I believe the answer is:
amazed
'dumbfounded' is the definition.
('amaze' can be a synonym of 'dumbfound')
'a labyrinth has daughter' is the wordplay.
'labyrinth' becomes 'maze' (synonyms).
'has' means one lot of letters go next to another.
'daughter' becomes 'd' (genealogical abbreviation).
'a'+'maze'+'d'='AMAZED'
(Other definitions for amazed that I've seen before include "Overwhelmed with wonder" , "Staggered" , "Completely surprised" , "Greatly surprised and impressed" , "knocked for six" .)