lasting for a short time; brief; fleeting 短暂的; 短促的; 飞逝的: a passing thought, fancy 闪现的念头﹑ 幻想. 
casual; cursory 随便的; 不经意的; 粗略的: a passing glance, reference, remark 顺便的看一眼﹑ 一提﹑ 一说.> passing n [U]
1 process of going by 经过: the passing of time, the years 时间﹑ 年月的流逝.
2 (fml 文) (a) end 末尾; 尽头: the passing of the old year, ie on New Year's Eve 除夕. (b) (euph 婉) death 去世: They all mourned his passing. 大家都对他的逝世表示悲痛.
3 (idm 习语) in passing casually; incidentally 随便地; 碰巧地; 顺便地: mention sth in passing 顺便提某事.