noun, na-adjective
Refers to playful mischief or a practical joke, similar to いたずら or 悪ふざけ. Often used in casual contexts.
彼の転合にはいつも笑わされる。
His pranks always make me laugh.
それはちょっとした転合のつもりだった。
It was meant as a little joke.
Ateji (phonetic) spelling; the kanji 転 and 合 (or 業) are used for their sounds rather than their meanings. The word itself is likely a native Japanese term, but its exact origin is uncertain.