Cactoid

Full definition of cactoid

Noun

1. A member of the cactus subfamily Cactoideae.
2. (topology)
• 1951, John William Theodore Youngs, The Representation Problem for Fréchet Surfaces (page 27)It is well known that a Peano space is a cactoid if and only if each of its true cyclic elements is a 2-sphere.