Invertebrate Taxonomy

in·ver·te·brate (ĭn-vûr' tə-brĭt, -brāt)
adj.

1. Lacking a backbone or spinal column; not vertebrate.
2. Of or relating to invertebrates: invertebrate zoology.

n.

An animal, such as an insect or mollusk, that lacks a backbone or spinal column. See figures below.