- synchronizing circuit
- synchronous detector
- synchronous hierarchy
- synchronous network
- synchronous orbit
- synchronous port
- synchronous system
- synchronous transmission
- syncword
- syntax diagram
- syntolic architecture
- system capacity
- system modification
- system program
- system provider
- system simulator
- system structure
- system tape
- system termination
- system user
- system variable
- T-antenna
- table column
- table definition
- tabulator mechanism
- tail
- tandem hops
- tandem system
- switched
- switching cycle
- switching device
- switching tube
- syllabic device
- symbol set
- symbolic coding
- symbolic notation
- synchronization circuit
- synchronization network
- synchronous detection
- synchronous idle
- synthesis programme
- system interval
- system load
- system loss
- system management
- system monitor
- system planning
- system profile
- system reset
- system resources
- system restart
- system security
- tab
- tabulation mark
- talk-off
- talker chip
- tandem paths
- tape calculator
- tape printing
- tape skip
- tapered distribution
- tangential modulus
- tape container
- tape deck
- tape drive
- tape recording
- tape speed
- tape-recorder
- tapered illumination
- target acquisition
- target signal
- targeting
- Tariff Structure
- TASI equipment
- task register
- technical expertise
- technical optics
- technical acknowledgement
- technical performance
- technical standards
- technical viewpoint
- technological aperture
- technological constraint
- technological opening
- tele
- tele-writer
- telecommand
- telecommunication
- telecommunication cable
- Telecommunication Journal
- telecommunication media
- telecommunication network
- telecommunication operator
- telecommunication system
- telecommunications
- telecommunications administration
- telecommunications line
- telecopy
- teledrawing
- telefascimile