- Subdural hematoma
- Subdural space
- Suberin
- Subfornical organ
- Subframe
- Subgame
- Subgame perfect equilibrium
- Subgrade
- Subgradients
- Subgranular zone
- Subgraph
- Subgraph isomorphism problem
- Subharmonic
- Subharmonic mixer
- Subiculum
- Subject access
- Subjective expected utility
- Subjective refraction
- Sublimation
- Sublingual
- Submanifold
- Submarine earthquake
- Submarine fans
- Submarine groundwater discharge
- Submarine landslides
- Submarine pipelines
- Submerged arc welding
- Submerged floating tunnel
- Submersible drilling rig
- Submersible pumps
- Submittals
- Submodular set function
- Submucosa
- Subnets
- Suborbital
- Suboxides
- Subring
- Subroutine
- Subscapularis
- Subscapularis muscle
- Subscription
- Subsetting
- Subsidence
- Subsoil
- Subsonic
- Subsonic aircraft
- Subspace topology
- Substance P
- Substances of very high concern
- Substantial equivalence
- Substation
- Substituent
- Substitute natural gas
- Substituted benzofuran
- Substitution
- Substitution ciphers
- Substitution reactions
- Substrate
- Substrate analog
- Substrate channeling
- Substrate coupling
- Substructure
- Subsumption architecture
- Subsurface flow
- Subsurface scattering
- Subtalar joint
- Subtended
- Subterranean
- Subthalamic nucleus
- Subthalamus
- Subthreshold conduction
- Subthreshold leakage
- Subthreshold slope
- Subtilisin
- Subtitles
- Subtraction
- Subtractor
- Subunit vaccine
- Subunits
- Subventricular zone
- Subversion
- Subvolcanic
- Subways
- Subwoofer
- Success
- Successive linear programming
- Succinaldehyde
- Succinate
- Succinate dehydrogenase
- Succinic acid
- Succinic anhydride
- Succinimide
- Sucker rod
- Sucrase
- Sucrose
- Suction
- Suction bucket
- Suction caisson
- Suction cups
- Suction hose
- Suction power
- Suction pressure
- Sudden unintended acceleration
- Sudo
- Suede
- Sufficient statistic
- Sufficiently large
- Suffix array
- Sugar
- Sugar alcohols
- Sugar beet
- Sugar phosphates
- Sugarcane
- Sugarcane wax
- Sugars
- Sugarscape
- Sugeno integral
- Suicide gene
- Suitability analysis
- Sulbactam
- Sulci
- Sulfadoxine
- Sulfamate
- Sulfamic acid
- Sulfanilic acid
- Sulfapyridine
- Sulfatase
- Sulfate attack
- Sulfate minerals
- Sulfate sulfite
- Sulfate-reducing bacteria
- Sulfenamide
- Sulfenic acid
- Sulfidation
- Sulfide minerals
- Sulfide stress cracking
- Sulfinamide
- Sulfite
- Sulfite oxidase
- Sulfite sulfate
- Sulfobetaine
- Sulfolane
- Sulfonates
- Sulfonation
- Sulfones
- Sulfonic acid
- Sulfonium
- Sulfonyl
- Sulfonyl chloride
- Sulforaphane