俳 ハイ unorthodox; actor; haiku

The 俳 in 俳句 (haiku) originally meant “unorthodox”. How did it come to be used for Japan’s most famous form of poetry?

Haiku were originally called hokka (発句). They were simply the starting verse of a renga, a collaborative poem written by two or more participants. Over the centuries, a more comical, down-to-earth, less aristocratic form of renga called haikai (俳諧) emerged, and heavily influenced haiku as it grew as an independent poetry form. At the end of the 19th century, the Japanese writer Masaoka Shiki proposed calling hokka “haikai no ku”, or “haiku” for short — and thus its modern name.