秒

countdown

speed per second

every second

second (unit of time)

one second

femtosecond chemistry

moment

to have no time to lose

stop watch

rapid progress

a few seconds

number of seconds

second hand (of clock)

winning in a flash

nanosecond

picosecond

microsecond

millisecond

watt-second

zeptosecond

five-second rule (food hygiene myth)

femtosecond

split second

in an instant

three-second rule (food hygiene myth)

decays per second

arc second

a moment

leap second