- nascent neutron
- natural draft
- natural radioactivy
- natural radionuclide
- needle dial
- negative carrier
- negative friction
- negative image
- negative print
- negative sleeve
- negative view
- net torque
- neutron source
- Newtonian fluid
- newtonian telescope
- natural uranium
- natural vibration
- near ultraviolet
- negative reactivity
- negatron
- network parameters
- neutralization pond
- neutretto
- neutrodyne
- neutron absorber
- neutron flux
- neutron optics
- nitometer-luxmeter
- nitride hardening
- non-conducting
- neutron
- neutron capture
- neutron diffraction
- newton
- nitrate base
- nitrided steel
- non-inductive
- nonkinking
- node
- nodular corrosion
- nonpolar dielectric
- noisy radiator
- non-conductive
- non-conductor
- noncontacting piston
- nondispersive medium
- nonlinear vibrations
- nonthermal neutron
- normalize
- northmost
- notch toughness
- nozzle exit
- nuclear abundance
- nuclear accident
- nuclear energetics
- nuclear isomerism
- nuclear molecule
- nuclear poison
- nucleation factor
- nuclei
- nucleon
- nucleus
- nonbonding electron
- noncontacting plunger
- normal
- normal coordinates
- normal pressure
- nozzle cowl
- nu-factor
- nuclear
- nuclear activity
- nuclear deformation
- nuclear moment
- nuclear neutron
- nuclear spectra
- nuclear theory
- nuclear track
- nucleon number
- nucleor
- oersted
- offset temperature
- ohmic
- OHV engine
- oil drop
- oil engine
- ocular
- off-gas
- oil fuel
- oil stimulation
- omnidiretional microphone
- oil-burning
- oil-quench
- on center
- onset
- opacity
- opaque
- opaque medium
- opaque substance
- operating lifetime
- operation area