China 
Africa 
- Parotid gland
- Paroxysmal supraventricular tachycardia
- Paroxysmal tachycardia
- Parquet
- Parry
- Pars plana
- Parsec
- Parseval's theorem
- Parshall flume
- Parsing
- Part number
- Part program
- Part-of-speech tagging
- Parthenium argentatum
- Parthenolide
- Partial agonist
- Partial autocorrelation function
- Partial charge
- Partial correlation
- Partial derivatives
- Partial differential equations
- Partial discharge
- Partial dislocations
- Partial element equivalent circuit
- Partial fraction decomposition
- Partial isometry
- Partial melting
- Partial molar property
- Partial order reduction
- Partial oxidation
- Partial pressure
- Partial thromboplastin time
- Partial wave analysis
- Partial-order planning
- Partial-wave analysis
- Partially ordered set
- Partially premixed combustion
- Participation
- Participation bias
- Participative decision-making
- Participatory culture
- Participatory design
- Participatory ergonomics
- Participatory management
- Particle acceleration
- Particle aggregation
- Particle board
- Particle counter
- Particle damping
- Particle density
- Particle deposition
- Particle displacement
- Particle filter
- Particle identification
- Particle in a box
- Particle mesh
- Particle number
- Particle physics
- Particle radiation
- Particle segregation
- Particle size
- Particle size analysis
- Particle size distribution
- Particle systems
- Particle technology
- Particle therapy
- Particle tracking velocimetry
- Particle velocity
- Particle-induced x-ray emission
- Particle-size distribution
- Particulate matter
- Particulate organic carbon
- Particulate pollution
- Particulates
- Partition coefficient
- Partition function
- Partition of a set
- Partition of unity
- Partition problem
- Partitions
- Parvalbumin
- Parvovirus
- Parvovirus b19
- Parylene
- Pascal
- Pascal matrix
- Pascal's Triangle
- Pascal's law
- Pass transistor logic
- Passaging
- Passband
- Passenger load factor
- Passenger terminal
- Passenger trains
- Passivated
- Passivation
- Passive attack
- Passive autocatalytic recombiner
- Passive cooling
- Passive diffusion
- Passive dynamics
- Passive fire protection
- Passive houses
- Passive infrared sensor
- Passive margins
- Passive matrix
- Passive monitoring
- Passive radar
- Passive safety
- Passive sampling
- Passive seismic
- Passive sign convention
- Passive smoking
- Passive solar
- Passive solar building design
- Passive survivability
- Passive transport
- Passive treatment system
- Passive ventilation
- Passivhaus
- Passphrase
- Password
- Password cracking
- Password manager
- Password strength
- Past medical history
- Paste
- Pasteurization
- Patch
- Patch antenna
- Patch clamp
- Patch tests
- PatchMatch
- Patched
- Patchwork
- Patchy particles
- Patella
- Patellar tendon
- Patellofemoral pain syndrome
- Patent
- Path analysis
- Path coefficients
- Path graph
- Path integral formulation
- Path integration
- Path loss
- Path protection
- Path tracing
- Pathfinding
- Pathogen