subs - taxi
- syncopation
- syncword
- syndiotactic polymer
- syndrome
- syndrome decoding
- syndrome testing
- synecology
- syneresis
- synergetic plane change maneuver
- synergetic plane change vehicle
- synergism
- synergistic effect
- synergy
- syngas
- SYNOP report
- synoptic climatology
- synoptic hour
- synoptic map
- synoptic meteorology
- synoptic method
- synoptic observations
- synoptic oceanography
- synoptic report
- synoptic scale
- synoptic situation
- synoptic station
- synoptician
- synoptics
- synroc
- syntactic analysis
- syntactic [syntax] analyzer
- syntactic(al) unit
- syntactic(al) unit
- syntax
- syntax checker
- syntax recognizer
- syntax-oriented compiler
- synthesis
- synthesis gas
- synthesized exciter