tuā-tsî大薯

a type of edible yam

a type of edible yam (larger but similar in shape to Chinese yam); purple yam; ube

English Wiktionary, “大薯” (CC BY-SA 4.0) — https://en.wiktionary.org/wiki/%E5%A4%A7%E8%96%AF · confidence: High (Wiktionary, Quanzhou/Jinjiang)