ㄅㄠˇbǎoㄓㄤˇzhǎng

  1. 宋史··》:熙寧王安石募兵相保十家一人保長。」

ㄅㄠˇbǎoㄔㄤˊcháng

  1. 鳳凰·劉向說苑··》:天老,……。發明」,保長」,飛鴻」,」。』」

(math.)​ distance-preserving, isometric, head of a bao 保[bao3] in the baojia 保甲[bao3 jia3] system