Tanka n. : A kind of boat used in Canton. It is about 25 feet long and is often rowed by women. Called also tankia.

Example:
How can i write a Tanka poem about a book called farewell to manzanar and how they feel?

Taxonomy
waka, tanka, poets, anthology, poem, English, Six best Waka poets, Thirty-six best Waka poets, AHA Books, poetry, Reichhold, Gualala, California, Jane Reichhold, chōka, English-language tanka, translation, Stanford University Press, court.

Defination from the web:
tanka (短歌, "short poem") and chōka (長歌, "long poem"), but also ... In the early Heian period (at the beginning of the 10th century), chōka was seldom written and tanka became the main form of waka. ...