Erratic Roman worried about daughter (6)
I believe the answer is:
random
'erratic' is the definition.
(thesaurus)
'roman worried about daughter' is the wordplay.
'worried' indicates anagramming the letters (worry can mean to interfere with or disturb).
'about' indicates putting letters inside.
'daughter' becomes 'd' (genealogical abbreviation).
'roman' anagrammed gives 'ranom'.
'ranom' placed around 'd' is 'RANDOM'.
(Other definitions for random that I've seen before include "Haphazard, no fixed pattern" , "Without order" , "'Haphazard, occurring by chance (6)'" , "Indiscriminate" , "Without a particular aim or purpose - say a choice" .)