- normal density
- Normal distribution
- normal polarity
- normal reaction
- normal sand
- normal stress
- normal weld
- normative pressure
- nose
- nosing
- notch fall
- notched bar
- notched burs
- notched spike
- note
- notorious
- novel
- novice
- nozzle
- nuclear radiation
- nuclear reaction
- non-turbulent
- non-uniform
- nondescriptor
- nondrying putty
- nonelastic bar
- noninterference coding
- nonlustrous finish
- nonmetallic materials
- nonrigid culvert
- nonsteady flow
- nonsubmerged overfall
- noodle
- Norfolk latch
- Normal architecture
- normal component
- normal condition
- normal depth
- normal environment
- normal lettering
- normal mode
- normal pressure
- normal section
- normal style
- normal throw
- normalization control
- normally
- norman
- normative stock
- north
- north-western
- northern light
- nosing line
- notch
- notch effect
- notch joint
- notchboard
- notched beam
- notched brick
- notched lung
- notched specimen
- notched trowel
- notching machine
- nourish
- noxious fumes
- nozzle holder
- nuclear
- nuisance
- number capacity
- numbering system
- numeric character
- numerical damping
- numerical data
- numerical indicator
- nut runner
- nut wrench
- nuts
- nutshell
- nylon mat
- obelisk
- oblique load
- oblique projection
- oblique slope
- oblique tenon
- null
- null pointer
- null reading
- number
- numerical calculation
- numerical information
- numerical integration
- nursery
- nursery garden
- nut bolt
- nut lock
- nylon rope
- O-ring
- object plane
- object properties
- object protection