Incisor or molar (5)
I believe the answer is:
tooth
I believe this clue is a double definition.
'incisor' is the first definition.
(I've seen this before)
'molar' is the second definition.
(I've seen this before)
(Other definitions for tooth that I've seen before include "One needed to chew" , "Taste" , "Incisor, e.g." , "In which the old are long" , "Biter" .)