Definition of "zeroid"

If a semigroup S contains a zeroid, then every left zeroid is also a right zeroid, and vice versa, and the set K of all the zeroids of S is the kernel of S.

1961, Alfred Hoblitzelle Clifford, G. B. Preston, The Algebraic Theory of Semigroups, page 70

Simplex zeroids seem to provide an alternative framework for discussing the themes broached in this paper, and of course Theorems 1—4 can be reexpressed in terms of simplex zeroids.

1993, Keith Walker, Surveys in combinatorics, 1993, page 166