[xiān xíng]
(走在前面) go ahead of the rest; start off before the others
Food and fodder should go ahead of troops and horses.
兵马未动, 粮草先行。
(预先进行) beforehand; in advance
notify in advance
先行通知
make preparations beforehand
先行准备
The new products will first be put on trial sale in this city.
这种新产品将在本市先行试销。