單ㄉㄢdān傳ㄔㄨㄢˊchuán

一師傳授而不雜別派。宋·楊萬里〈書黃廬陵伯庸詩卷〉詩：「句法何曾問外人，單傳山谷當家春。」
世代相傳僅有一子者。

英to have only one heir in a generation (of a family, clan etc), to be learned from only one master (of a skill, art etc)