zeptosecond

1. (metrology) An SI unit of time equal to 10⁻²¹ seconds. Symbol: zsExamples: "Holonyms: attosecond < femtosecond < picosecond < nanosecond < microsecond < millisecond < centisecond < decisecond < second < decasecond < minute < hectosecond < kilosecond < hour < day < week < megasecond < fortnight < month < year < gigasecond < century < kiloannum, kiloyear, millennium < terasecond < mega-annum, megayear < petasecond < giga-annum, gigayear < exasecond < zettasecond < yottasecond < ronnasecond < quettasecond"; "Meronyms: quectosecond < rontosecond < yoctosecond"