- directed group
- directed infinity
- directed limit
- directed line
- directed line-segment
- directed network
- directed order
- directed path
- directed plane
- directed point set
- directed quantity
- directed quasiorder
- directed segment
- directed set
- directed strongly regular graph
- directed system
- directed tetrahedron
- directed tree
- directed union
- directed value
- direct factor
- direct homothety
- crash duration
- Crawford, L.
- Cray, S.