Word of the Day:

: harmful

"Poorly tuned engines can put out up to 800 times the nocuous emissions of properly maintained ones." (PR Newswire, January 7, 1992)

You are probably more familiar with the adjective "innocuous," meaning "harmless," than with its antonymous relative "nocuous." Both "nocuous" and "innocuous" have immediate Latin predecessors: "nocuus" and "innocuus." (The latter combines "nocuus" with the negative prefix "in-.") Both words can also be traced back to the Latin verb "nocēre," meaning "to harm." Other "nocēre" descendants in English include "innocent" and "nocent," which means "harmful." "Nuisance" (which originally meant, and still can mean, "a harm or injury") is a more distant relative. "Nocuous" is one of the less common "nocēre" descendants, but it does turn up occasionally.