Large mat is made for one with two families (8)
I believe the answer is:
bigamist
'for one with two families' is the definition.
I can't judge whether this definition defines the answer.
'large mat is made' is the wordplay.
'large' becomes 'big' (synonyms).
'made' indicates an anagram.
'mat'+'is'='matis'
'matis' with letters rearranged gives 'amist'.
'big'+'amist'='BIGAMIST'
Can you help me to learn more?
(Other definitions for bigamist that I've seen before include "One with a partner too many" , "One marries while already legally married to another" , "Man with two wives" , "One who unlawfully marries a second wife" , "Person who marries while still married to another" .)