- flat bundle
- flat chain
- flat cochain
- flat connection
- flat covering
- flat deformation
- flat dimension
- flat distribution
- flat embedding
- flat extension
- flat F-bundle
- flat form
- flat function
- flat function germ
- flat graph
- flat holomorphic mapping
- flat ideal
- flat manifold
- flat mapping
- flat metric
- flat module
- flat morphism
- flatness
- flatness theorem
- flat norm