Nocuous (adjective) .- Something that’s nocuous (NAHK-yoo-us) is harmful, likely to cause damage or injury. As used by the Indian spiritual leader Guru Nanak (1469-1539): “[The king] shall use his utmost exertions to remove those men who are nocuous like thorns. [He] shall cause a goldsmith who behaves dishonestly, the most nocuous of all the thorns, to be cut to pieces with razors.”