verse form vs tanka

verse form and tanka both are nouns.

Word	Noun	Adjective	Verb	Adverb
verse form	Yes	No	No	No
tanka	Yes	No	No	No

As nouns, tanka is a hyponym of verse form; that is, tanka is a word with a more specific, narrower meaning than verse form:

verse form: a composition written in metrical feet forming rhythmical lines
tanka: a form of Japanese poetry; the 1st and 3rd lines have five syllables and the 2nd, 4th, and 5th have seven syllables

verse form (noun)	tanka (noun)
a composition written in metrical feet forming rhythmical lines	a Tibetan religious painting on fabric
	a form of Japanese poetry; the 1st and 3rd lines have five syllables and the 2nd, 4th, and 5th have seven syllables