巫山戯る

ふざける (to joke; to frolic) is sometimes written as 巫山戯る. Why?

There is a story in China, where King Huai of Chu (懐王) saw a dream where he laid with a goddess from the mysterious Wu Mountains (巫山). You could say, the two frolicked. Considering that the character 戯 means “to play; to frolic”, if we add it to 巫山, we get 巫山戯る — to joke, to kid; to frolic, the “to joke” meaning probably coming from the surreal nature of this dream. There we have a story within a single word, and that’s the reason I love writing out kanji for words which are usually written in kana.

As for the reading: the first part, 巫山, is read ふざん. It would be difficult to say ふざんける, so the ん was dropped. The ける part was developed in modern Japanese; the original word was ふざく and didn’t have space to house the 戯 character. Technically speaking, the word simplified into 一段活用. In an alternate reality, it could’ve developed into ふざかる. Anyway, the character 戯 needed to go somewhere, so it was stuck as the sound け (after ふざ). Indeed, 戯 doesn’t have a reading け-る outside of the word ふざけ-る. The fact that some kanji are forced into a reading like this is a fascinating phenomenon in Japanese.