Answer:

psec

AnswerCrossword Clue
PSECUltrashort time unit: abbr.
PSECOne 60-trillionth of a min.
PSECMinute segment of a min.
PSECTiny fraction of a min.
PSECTiny time meas.
PSECInfinitesimal division of a min.
PSECVery brief time, briefly
PSECMin. fraction
PSEC1-60 of a trillionth of a min.
PSECInfinitesimal fraction of a min.
PSECVery brief time
PSECTeeny fraction of a min.
PSECTiny time unit (abbr.)
PSECMinute part of a minute, for short
PSECTime it takes for light to travel .3 mm
PSECThere are 60 trillion in a min.
PSECTime it takes light to travel .3 mm: Abbr.