- Paperboard
- Papillae
- Papillary muscles
- Papilledema
- Papilloma
- Papillomavirus
- Paprika
- Parabens
- Parabolas
- Parabolic
- Parabolic antenna
- Parabolic arches
- Parabolic partial differential equation
- Parabolic reflectors
- Parabolic troughs
- Paraboloids
- Parabrachial nucleus
- Paracellular
- Paracellular transport
- Paracetamol
- Parachutes
- Paracoccus denitrificans
- Paracrine
- Paracrystallinity
- Paradigm
- Paradox Basin
- Paradox of material implication
- Paradoxes
- Paradoxical embolism
- Paraffin deposition
- Paraffin wax
- Parafoil
- Paraformaldehyde
- Parafovea
- Paraganglioma
- Paragenesis
- Paragonite
- Parahippocampal gyrus
- Parahydrogen
- Parainfluenza
- Paraldehyde
- Paralinguistic
- Parallax
- Parallax barriers
- Parallax scrolling
- Parallel algorithms
- Parallel analysis
- Parallel axis theorem
- Parallel communication
- Parallel computing
- Parallel coordinates
- Parallel curves
- Parallel database
- Parallel manipulator
- Parallel motion
- Parallel port
- Parallel processing
- Parallel programming model
- Parallel projection
- Parallel rendering
- Parallel tempering
- Parallel transport
- Parallel-strand lumber
- Parallelepipeds
- Parallelizable
- Parallelization
- Parallelogram
- Parallelogram law
- Paralysis
- Paramagnetism
- Paramelaconite
- Parameter identification problem
- Parameter space
- Parametric
- Parametric amplifier
- Parametric design
- Parametric equations
- Parametric family
- Parametric oscillator
- Parametric programming
- Parametric statistics
- Parametric surface
- Parametrization
- Paramyxoviridae
- Paranasal sinuses
- Paraoxonase
- Parapets
- Paraphrasing
- Paraphyletic
- Paraplegia
- Paraquat
- Parasequence
- Parasitemia
- Parasitic
- Parasitic capacitance
- Parasitic diseases
- Parasitic drag
- Parasitic elements
- Parasitic extraction
- Parasitic resistance
- Parasitoids
- Parasitophorous vacuole
- Parasolid
- Parasympathetic
- Parasympathetic nervous system
- Paratacamite
- Parathion methyl
- Parathyroid adenoma
- Parathyroid gland
- Parathyroid hormone
- Parathyroid hormone 1 receptor
- Paratope
- Paratransit
- Paraventricular nucleus
- Paraview
- Paraxanthine
- Paraxial approximation
- Parenchyma
- Parent compound
- Parent process
- Parent rock
- Parenteral
- Parentheses
- Paresis
- Paresthesia
- Pareto Principle
- Pareto analysis
- Pareto chart
- Pareto distribution
- Pareto front
- Pareto frontier
- Parietal cells
- Parietal lobe
- Parieto-occipital sulcus
- Paris' law
- Parisite
- Parisite-
- Parity bit
- Parity of a permutation
- Parity-check matrix
- Park and ride
- Parkerian Hexad
- Parking brake
- Parking garage
- Parking lot
- Parking meters
- Parking orbit
- Parkinson's disease
- Parkinsonism
- Parkways