保长

保长	bǎo cháng	(math.) distance-preserving / isometric
保长	bǎo zhǎng	head of a bao 保 in the baojia 保甲 system
保	Bǎo	Bulgaria (abbr. for 保加利亚)
保	bǎo	to defend; to protect; to keep / to guarantee; to ensure / (old) civil administration unit in the baojia 保甲 system
长	cháng	long / (bound form) length / (bound form) strong point; forte / (bound form) to be good at / (literary) surplus; spare (Taiwan pr. [zhang4])
长	zhǎng	chief / head / elder / to grow / to develop / to increase / to enhance