Fit metal tip that's shaped (5,3)
I believe the answer is:
petit mal
'fit' is the definition.
(petit mal is a kind of fit)
'metal tip that's shaped' is the wordplay.
'that's shaped' indicates an anagram.
'metal'+'tip'='metaltip'
'metaltip' with letters rearranged gives 'PETIT MAL'.
(Other definitions for petit mal that I've seen before include "Mild attack of epilepsy (French)" , "Mild epilepsy - metal tip (anag)" .)