schl - semi
- secondary sources method
- secondary spiral
- secondary standards
- secondary steel-making
- secondary storage tank
- secondary surveillance radar
- secondary tank
- secondary timber
- secondary transition
- secondary transport
- secondary treatment
- secondary treatment plant
- secondary tree species
- secondary well
- secondary yield
- secondary-electron conductivity
- secondary-electron spectroscopy
- secrecy communications
- secret application
- secret key
- secret patent
- secret prior use
- secret telephone installation
- secret use
- secretagogue(s)
- secretagogue(s)
- secretary extension
- secretary transfer
- secretor gene
- section
- section assignment table
- section change
- section changing
- section conveyor belt
- section factor
- section lightning arrester
- section lineman
- section milling
- section modulus
- section of complete mixing
