A formal system which extends first-order logic by allowing quantification over relations between members of the universe.

plural of frame per second

Any rule that prescribes or proscribes behavior in a three-second interval, especially

Any rule that prescribes or proscribes behavior during a ten-second interval, especially:

A rapid and severe brain swelling caused by a second concussion before a first has sufficiently healed, such as may occur after suffering two concussions during the same sports match. It has catastrophic results and may cause death or permanent disability.

plural of second impact syndrome

A measure of kinematic viscosity used in classical mechanics: the time taken by 60 cm³ of oil to flow through a calibrated tube at a controlled temperature of 38°C.

plural of Saybolt universal second

(idiomatic) A time that will never come.

escape velocity of Earth (interplanetary speed)