Selachii is a term used to describe a group of fish species that are commonly referred to as sharks. However, there are other synonyms for this word that can be used to refer to these fascinating creatures. One synonym is the word "elasmobranch" which encompasses both sharks and rays. Another common synonym for sharks is "selachimorpha." This term refers specifically to the class of cartilaginous fish to which sharks belong. Other synonyms include "squaloids" and "palaeoselachians" which describe specific groups or traits of sharks. Regardless of the term used, sharks are some of the most awe-inspiring creatures in the ocean and continue to captivate scientists and laypeople alike.