- symplectic transformation
- symplectic transformation group
- symplectic transvection
- symplectic vector field
- symplectic vector space
- symplectomorphism
- syncategorematic word
- synchro control
- synchro error
- synchronism
- synchronization
- synchronization error-correction code
- synchronization mechanism
- synchronization of terminals
- synchronous
- synchronous computing method
- synchronous performance
- synchronous superposition
- synchronous system
- synclastic
- synclinal line
- syncline
- syndrome
- syndrome polynomial
- synentropy