- semigroup with zero
- semi-hereditary ring
- semi-homomorphism of rings
- semi-implicit mid-point method
- semi-inner product
- semi-interior
- semi-interquartile range
- semi-involution
- semi-isomorphism of rings
- semi-iterative method
- semilattice
- semilattice
- semilattice
- semilinear mapping
- semilinear monomial representation
- semi-linear partial differential equation
- semilinear transformation
- semi-linear transformation
- semilinear transformation group
- semilocal(commutative) ring
- semi-local ring
- semi-low set
- semi-Markov process
- semimartingale
- semi-matroid of polytope