(neologism) (slang) to respond to a message within seconds

(Internet) flash sale

(time) second

stopwatch

a stopwatch [written and colloquial]

parsec (astronomy)

nanosecond, ns, 10^-9 s (PRC)

picosecond, ps, 10^-12 s

second of arc; 1/1296000 of a circle

(coll.) to take in at a glance

to count the number of seconds (between two events)

(physics) attosecond (10⁻¹⁸ s)

to count down the remaining seconds (e.g. in games, rocket launches, New Year's Eve)

femtosecond, fs, 10^-15 s

to understand instantly

to ejaculate within a few seconds during sex

microsecond, µs, 10^-6 s

metre per second, m/s

second hand (of a clock)

nanosecond, ns, 10^-9 s (Tw)

seize every minute and second (idiom); not a minute to lose

millisecond, ms