Molar or incisor for instance (5)
I believe the answer is:
tooth
This clue is a double definition.
'molar' is the first definition.
(I've seen this in another clue)
'incisor for instance' is the second definition.
(I know that incisor is a type of tooth)
(Other definitions for tooth that I've seen before include "Gearwheel cog" , "for drilling and extraction" , "One needed to chew" , "Taste" , "Canine or incisor?" .)