-cide

forms words naming an act of killing or the person or substance that kills

Spelled -cide · -cidium 'a killing' and -cida 'killer,' from caedere 'cut down, kill'

Latin caedere meant cut down or kill; homicide names human killing, regicide a ruler's killing, and pesticide the killing of pests.

Words built from it

homicide — the killing of one person by another
homi- (human) + -cide (killing)
suicide — the act of intentionally killing oneself
sui- (oneself) + -cide (killing)
genocide — the deliberate destruction of a national, ethnic, racial, or religious group
geno- (race or people) + -cide (killing)
pesticide — a substance used to kill pests
pest (harmful creature or plant) + -cide (killer)
regicide — the killing of a monarch, or the person responsible
regi- (king or ruler) + -cide (killing or killer)
fratricide — the killing of one's brother
fratri- (brother) + -cide (killing)

-able/-ible — turns a verb into an adjective meaning capable of, fit to be, or worthy of the action
-al — turns a noun or root into an adjective meaning related to or characterized by it
-en — turns an adjective or noun into a verb meaning to make or become that quality
-ful — turns a noun into an adjective meaning full of or strongly marked by it
-ic — turns a noun into an adjective meaning related to or characterized by it