- natural frequency of structure
- natural homomorphism
- natural homomorphism of a group
- natural homomorphism of Boolean algebras
- natural increasing process
- natural language processing
- natural language understanding
- natural logarithm
- natural logarithmic function
- natural logarithm table
- natural mapping
- natural method
- natural monomorphism
- natural number
- natural number
- natural number of a logarithm
- natural numbers
- natural number table
- natural order on an inverse semigroup
- natural parameter
- natural parameter
- natural parameter of a straight line
- natural partial congruence
- natural spline
- natural system