Man overcome by one daughter’s literary style (5)
I believe the answer is:
idiom
'literary style' is the definition.
(idiom can mean a style or manner of expression)
'man overcome by one daughter's' is the wordplay.
'man' becomes 'iom' (abbreviation for Isle of Man).
'overcome by' means one lot of letters go next to another (in a down clue, some letters go over others).
'one' becomes 'I' (Roman numeral).
'daughter' becomes 'd' (genealogical abbreviation).
'i'+'d'='id'
'iom' put after 'id' is 'IDIOM'.
(Other definitions for idiom that I've seen before include "Group of words in which the meaning may not be obvious" , "Colloquialism" , "Saying specific to a certain language" , "Form of linguistic expression" , "Expression that does not make literal sense" .)