Not suitable (13)
There are a few possibilities for this:
inappropriate
(Other definitions for unfit that I've seen before include "struggling to keep up?" , "Incapable" , "Ill-suited" , "Not healthy" , "Not prepared" .)
'not suitable' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for inapt that I've seen before include "Out of place" , "Unsuitable - paint (anag)" , "Unsuited" , "Cartoon duck" , "Not fit, unsuitable" .)
'not suitable' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for inappropriate that I've seen before include "Out of place" , "Not suitable" , "Improper" , "Unfitting" , "Unsuitable" .)