Nocuous [NAHK-yoo-əs]  

Part of speech: adjective 

Origin: Latin, mid-17th century  

1. Noxious, harmful, or poisonous.  

Examples of nocuous in a sentence  

"The lab techs wore close-fitting face masks to protect them from the nocuous liquids they were mixing."  

"Removing the nocuous plants growing behind the garden was a complicated job."