Definition of "monophyletic"

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

(biology) Deriving from a single clade (monophylum).

(biology) Descending from a single ancestral species.

1. Descending from a single ancestral species and containing all descendants of that single ancestor, holophyletic.  examples

2. Descending from a single ancestral species but not containing all descendants of that ancestor, paraphyletic.  examples

(biology) congeneric