Lisa's first day out as an aristocrat (4)
I believe the answer is:
lady
'an aristocrat' is the definition.
(I know that lady is a type of aristocrat)
'lisa's first day out' is the wordplay.
'lisa's first' becomes 'l' (1st letter of 'lisa').
'out' is an anagram indicator (out can mean wrong or inaccurate).
'day' is an anagram of 'ady'.
'l'+'ady'='LADY'
'as' acts as a link.
(Other definitions for lady that I've seen before include "Woman, of refinement perhaps" , "Wife of gentleman" , "See 20" , "See 7" , "See 19" .)