故交,故旧
gùjiāo,gùjiù
[old friends and acquaintances;close friend of many years' standing] 旧友,老朋友,老相识
红颜意气尽,白璧故旧轻。——唐·卢照邻《羁卧山中》
故旧不遗,则民不偷。——《论语·秦伯》(不偷:不薄,厚道)