adj. Of, pertaining to, or affecting a single phylum (or other taxon) of organisms.
adj. Deriving from a single clade (monophylum).
the GNU version of the Collaborative International Dictionary of English
adj. Of or pertaining to a single family or stock, or to development from a single common parent form; -- opposed to polyphyletic.
The Century Dictionary and Cyclopedia
Of or pertaining to a single phylum: said of a group of any grade in zoology, with reference to the origin of all the members of such group from a common ancestor: opposed to polyphyletic.
Word Usage
"Hennig's idea that groups of organisms, or taxa, should be recognized and formally named only in cases where they are evolutionarily real entities, that is "monophyletic", at first was controversial."