the.com/seconds
The base unit of time, also the polite word for going back for more.
means The SI unit of time, equal to one tick of the clock; also a second helping of food.
from From the Latin secunda pars minuta, the second small part of an hour after the first division into minutes.
Atomic clockDefined by cesium atoms vibrating 9,192,631,770 times.
HeartbeatRoughly one resting beat per second for adults.
Leap secondOccasionally added to keep clocks matching Earth's wobble.