a: any of an order (Hemiptera and especially its suborder Heteroptera) of insects (such as an assassin bug or chinch bug) that have sucking mouthparts, forewings thickened at the base, and incomplete metamorphosis and are often economic pests
called also true bug
b: any of various small arthropods (such as a beetle or spider) resembling the true bugs
c: any of several insects (such as a head louse) commonly considered obnoxious
“a: any of an order (Hemiptera and especially its suborder Heteroptera) of insects (such as an assassin bug or chinch bug) that have sucking mouthparts, forewings thickened at the base, and incomplete metamorphosis and are often economic pests”
This is the primary and most correct definition of bug.
Yes, people use it wrong. That doesn’t change the definition of the word.
Merriam-Webster, definition 1:
“a: any of an order (Hemiptera and especially its suborder Heteroptera) of insects (such as an assassin bug or chinch bug) that have sucking mouthparts, forewings thickened at the base, and incomplete metamorphosis and are often economic pests”
This is the primary and most correct definition of bug.
Yes, people use it wrong. That doesn’t change the definition of the word.
Actually it does, that’s how language works.
If enough people use it wrong, it becomes right.
Now you get to learn the difference between descriptive and prescriptive definitions.