Pseudo-traditional harmonic functions of enneatonic scale degrees

Degree number	Function	Regular tetrad
I	Tonic	I-III-V-VII
II	Supertonic	II-IV-VI-VIII
III	Comediant	III-V-VII-IX
IV	Subdominant	IV-VI-VIII-I
V	Submediant	V-VII-IX-II
VI	Mediant	VI-VIII-I-III
VII	Dominant	VII-IX-II-IV
VIII	Cosubmediant	VIII-I-III-V
IX	Leading tone Subtonic	IX-II-IV-VI

For terms like enneatonic see

Anhemitonic scale #Miscellanea - Wikipedia