“除草剂”的英语可以翻译为：herbicide，weedicide ...

经过反复施用除草剂，杂草得以彻底根除。With repeated applications of weedkiller, the weeds were overcome.这种除草剂在潮湿的土壤中分解.This herbicide degrades in moist soil.杂草对某些除草剂的抗药性已显现出来.Resistance of weeds to certain herbicides is beginning toshow up...