Gnat and Pest

Gnat noun - Any of various small biting flies: midges; biting midges; black flies; sand flies.

Pest and gnat are semantically related. in bug topic. In some cases you can use "Pest" instead a noun "Gnat", when it comes to topics like insect.

Pest noun - A widespread disease resulting in a high rate of death.

Gnat and pest are semantically related. Sometimes you can use "Gnat" instead a noun "Pest".