What is the meaning of Cereus?

Any of the genus Cereus of plants of the cactus family, natives to the Americas, from California to Chile.

of wax, waxen

of the colour of wax

of the properties of wax; soft, pliant

easily moved, swayed or persuaded

a wax taper or light, particularly those that were brought by clients to their patrons as presents at the time of the Saturnalia

Source: wiktionary.org