A class or other large division of invertebrated animals, to which different limits have been assigned.

noun plural. One of the classes of Arthropoda, including those that have one pair of antennæ, three pairs of mouth organs, and breathe air by means of tracheæ, opening by spiracles along the sides of the body. In this sense it includes the Hexapoda, or six-legged insects and the Myriapoda, with numerous legs. See insect, n.

noun plural. In a more restricted sense, the Hexapoda alone. See Hexapoda.

noun plural. In the most general sense, the Hexapoda, Myriapoda, and Arachnoidea, combined.

noun. insects; about five-sixths of all known animal species

"It is hard to believe that they all belong to the same family called insecta, but they do. ""

class  

Insecta  

Hexapoda  insect