Insecticide is a type of chemical used to kill insects, like those that have infested a house or a farmer's crops. Words that end in -cide usually have to do with killing, such as genocide, suicide, and patricide. Another is insecticide, which is a word for a substance that kills insects and bugs.Insecticides are substances that are in use to kill insects. Insecticides include ovicides and larvicides. These are in use against insect eggs and larvae. Insecticides are in use in the field of agriculture, medicine, industry and consumers.