The word insecticide refers to therapeutic agents - including natural substances such as herbs, oils, or essences, or conventional pharmaceutical drugs, that repels insects. Other definitions state that the term insecticide refers to preparations that kill or destroy disease-carrying insects, as implied by the structure of the word:
That is, the word insecticide has two parts:
- The -cide part of the word refers to the fact that this agent kills/destroys something, and
- the insecti- part of the word indicates that the something it kills is "insects".