As an alternative, left of the nose (5)
I believe the answer is:
nasal
'of the nose' is the definition.
(I've seen this before)
'as an alternative left' is the wordplay.
'alternative' indicates anagramming the letters.
'left' becomes 'l' (common abbreviation).
'as'+'an'='asan'
'asan' anagrammed gives 'nasa'.
'nasa'+'l'='NASAL'
(Other definitions for nasal that I've seen before include "Relating to a facial organ" , "Beak's" , "regarding the nose" , "Relating to the nose" , "Relating to one's hooter" .)