- left (right) H-algebra
- left(right) hereditary ring
- left (right) ideal of semigroup
- left(right) integral
- left (right) Noetherian ring
- left (right) order ring
- left (right) parametrix
- left (right) quotient ring
- left(right) regular module
- left(right) regular representation
- left(right) serial ring
- left (right)simple semigroup
- left (right) stabilizer
- left(right) trunction
- left screw
- left-sided sequence
- left side view
- left S-system
- left translation
- left translation
- legal measurement unit
- legal time
- Legendre acute angle proposition
- Legendre condition
- Legendre equation