There are several synonyms for the word "herbicides," which refer to substances used to kill or control weeds. One synonym is "weed killer," which specifically targets unwanted plants in gardens, lawns, and other outdoor environments. Another synonym is "pesticide," which encompasses a broader range of substances used to control insects, rodents, and other pests. "Fungicide" and "bactericide" are also sometimes used as synonyms for herbicides, as they target specific types of plant pathogens. Additionally, terms like "weed control agents" or "weed management tools" can also be used to describe herbicides and other measures taken to control the growth of unwanted plants.