Monophyly is a related term of monophyletic.

As an adjective monophyletic

is of, pertaining to, or affecting a single phylum (or other taxon) of organisms.

As a noun monophyly is

in cladistics, the condition of being monophyletic, of including all descendants from a given ancestral species.

As nouns the difference between descendant and monophyly

is that descendant is one who is the progeny of a specified person, at any distance of time or through any number of generations while monophyly is in cladistics, the condition of being monophyletic, of including all descendants from a given ancestral species.

As an adjective descendant

is descending from a biological ancestor.

As an adjective ancestral

is of, pertaining to, derived from, or possessed by, an ancestor or ancestors; as, an ancestral estate.

As a noun monophyly is

in cladistics, the condition of being monophyletic, of including all descendants from a given ancestral species.

As nouns the difference between species and monophyly

is that species is a type or kind of thing while monophyly is in cladistics, the condition of being monophyletic, of including all descendants from a given ancestral species.

As nouns the difference between amphibian and gnathostome

is that amphibian is an animal of the amphibia; any four-legged vertebrate that does not have amniotic eggs, living both on land and in water while gnathostome is (zoology) any vertebrate with jaws, including amphibians, reptiles, mammals, and most modern fish.

As an adjective amphibian

is (obsolete) having two natures or amphibian can be of or relating to the amphibians amphibia.

As nouns the difference between reptile and gnathostome

is that reptile is while gnathostome is (zoology) any vertebrate with jaws, including amphibians, reptiles, mammals, and most modern fish.

As nouns the difference between mammal and gnathostome

is that mammal is an animal of the class mammalia, characterized by being warm-blooded, having hair and feeding milk to its young while gnathostome is (zoology) any vertebrate with jaws, including amphibians, reptiles, mammals, and most modern fish.

As a proper noun fish

is .

As a noun gnathostome is

(zoology) any vertebrate with jaws, including amphibians, reptiles, mammals, and most modern fish.

As an adjective cladistic

is of, relating to, or generated using cladistics.

As a noun ingroup is

in cladistics, the monophyletic group that includes all taxa of interest to the current study.

As an adjective monophyletic

is of, pertaining to, or affecting a single phylum (or other taxon) of organisms.

As a noun ingroup is

in cladistics, the monophyletic group that includes all taxa of interest to the current study.