- any of various plants of the genus Cereus, of the cactus family, having large, usually white, funnel-shaped flowers.
- any of several related, similar plants, especially of the genera Hylocereus, Nyctocereus, and Selenicereus.
- any tropical American cactus of the genus Cereus, esp C. jamacaru of N Brazil, which grows to a height of 13 metres (40 feet)
- any of several similar and related cacti, such as the night-blooming cereus
