Shared Derived Characteristics: one that evolved in the lineage leading up to a clade and that sets members of that clade apart from other individuals

Shared Ancestral Characteristics: character or trait state shared by two or more taxa.

Paraphyletic: descended from a common evolutionary ancestor or ancestral group, but not including all the descendant groups

Monophyletic: descended from a common evolutionary ancestor or ancestral group, especially one not shared with any other group

Polyphyletic: derived from more than one common evolutionary ancestor or ancestral group and therefore not suitable for placing in the same taxon