Sunna vs Sunnah

Sunna and Sunnah both are nouns.

Word	Noun	Adjective	Verb	Adverb
Sunna	Yes	No	No	No
Sunnah	Yes	No	No	No

As nouns, Sunna and Sunnah are synonyms defined as:

Sunna and Sunnah: (Islam) the way of life prescribed as normative for Muslims on the basis of the teachings and practices of Muhammad and interpretations of the Koran

Other synonyms of Sunna include hadith.

Sunna (noun)	Sunnah (noun)
(Islam) the way of life prescribed as normative for Muslims on the basis of the teachings and practices of Muhammad and interpretations of the Koran	(Islam) the way of life prescribed as normative for Muslims on the basis of the teachings and practices of Muhammad and interpretations of the Koran