osteichthyes definition
Freebase(0.00 / 0 votes)Rate this definition: Osteichthyes. Osteichthyes, also called bony fish, are a taxonomic group of fish that have bone, as opposed to cartilaginous, skeletons. The vast majority of fish are osteichthyes, which is an extremely diverse and abundant group consisting of 45 orders, and over 435 families and 28,000 species.