- free-air anomaly
- free-air correction
- free algebra
- free BCI-algebra
- free BCK-algebra
- free Boolean algebra
- free boundary problem
- Freedman theorem on topological 4-manifolds
- free edges of polyhedral faces
- free extension of a partialely ordering group
- free filter
- free f-module
- free frequency of structure
- free group
- free Jordan algebra
- free K-{0,1}-distributive product
- free K-{0,1}-product
- free K-product
- free lattice
- free lattice-ordered group
- freely generated lattice
- free module
- free monoid
- free network adjustment
- free nonassociative algebra