Nothing unreasonable about way one refuses to face reality (7)
I believe the answer is:
ostrich
'one refuses to face reality' is the definition.
(ostriches put their heads in the sand)
'nothing unreasonable about way' is the wordplay.
'nothing' becomes 'O' (O resembles 0).
'unreasonable' becomes 'rich' ('that's rich coming from you!').
'about' is a charade indicator (letters next to each other).
'way' becomes 'st' (abbreviation for street).
'rich' after 'st' is 'strich'.
'o'+'strich'='OSTRICH'
(Other definitions for ostrich that I've seen before include "Rich sot seeks large bird" , "Chorist (anag.)" , "Torch is held over large bird" , "Someone unprepared to face the facts" , "Large flightless bird of Africa" .)