Each of a pair of claw-like sclerites, one on either side of the mouth, that function as feeding apparatus in the larvae of dipterous flies of the division (or suborder) Cyclorrhapha.
Origin
1930s.
Definition of mouth hook in US English:
mouth hook
noun
Entomology
Each of a pair of claw-like sclerites, one on either side of the mouth, that function as feeding apparatus in the larvae of dipterous flies of the division (or suborder) Cyclorrhapha.