- plain tricolour
- plain waterway regulation
- plain weave
- plain weave silk and damask on plain weave
- plakea
- Plakha
- plalar end
- plan
- Plana
- plan adjustment and market regulation
- Plan and Implement of Museum Exhibitions
- planar
- planar alignment
- planar arrangement of lines
- planar body
- planar chirality
- planar chromatography
- planar configuration
- planar connected graph
- planar contact network
- planar coordinate
- planar crossed force system
- planar crystallographic group
- planar curve
- planar defect