shivah vs shiva

shivah and shiva both are nouns.

Word	Noun	Adjective	Verb	Adverb
shivah	Yes	No	No	No
shiva	Yes	No	No	No

As nouns, shivah and shiva are synonyms defined as:

shivah and shiva: (Judaism) a period of seven days of mourning after the death of close relative

Other synonyms of shivah include shibah.

shivah (noun)	shiva (noun)
(Judaism) a period of seven days of mourning after the death of close relative	(Judaism) a period of seven days of mourning after the death of close relative