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a learned borrowing from Latin meaning “killer,” “act of killing,” used in the formation of compound words: pesticide, homicide.
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Origin of -cide

late Middle English, from Middle French, from Latin -cīda “killer,” -cīdium “act of killing,” derivatives of caedere “to strike, beat, cut down, kill” (in compounds -cīdere )
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022


What does -cide mean?

The combining formcide is used like a suffix meaning “killer” or “act of killing.” It is often used in a variety of scientific and technical terms.

The form –cide ultimately comes from Latin caedere, meaning “to kill, to strike down.”

What are variants of –cide?

While –cide does not have any variants, it is related to the combining form cidal, which is used to form adjectives that correspond to nouns ending in –cide, as in patricidal. Want to know more? Read our Words That Use article on –cidal.

Examples of -cide

An example of a word you may have encountered that features –cide is pesticide, also known as a biocide, “a chemical preparation for destroying plant, fungal, or animal pests.”

The pest part of the word means “pest,” from Latin pestis, meaning “plague.” A pest is an insect or other organism that causes destruction or illness. The –cide part of the word means “killer.” Pesticide literally translates to “pest killer.”

What are some words that use or are related to the combining form –cide?

What are some other forms that –cide may be commonly confused with?

Break it down!

The combining form cyto means “cell.” With this in mind, what does the scientific term cytocide literally mean?

How to use -cide in a sentence

British Dictionary definitions for -cide


n combining form
indicating a person or thing that killsinsecticide
indicating a killing; murderhomicide

Derived forms of -cide

-cidal, adj combining form

Word Origin for -cide

from Latin -cīda (agent), -cīdium (act), from caedere to kill
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for -cide


A suffix that means “a killer of.” It is used to form the names of chemicals that kill a specified organism, such as pesticide, a chemical that kills pests.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.