Origin: Latin suffix -ate
Invertebrate has 4 different meanings across 2 categories:
any animal lacking a backbone or notochord; the term is not used as a scientific classification
An animal without vertebrae, i.e. backbone.
lacking a backbone or spinal column
"worms are an example of invertebrate animals"
Lacking a backbone.
The word comes from the prefix in- combined with vertebrate. It literally means "not having a backbone."