femto-

1. a combining form used in the names of units of measurement which are 10− 15 (one quadrillionth) smaller than the unit denoted by the base word.

femto-

prefix

1. denoting 10 ^–15 f

   femtometer

Word History and Origins

Origin of femto-¹

< Danish, Norwegian femt ( en ) fifteen + -o-

Word History and Origins

Origin of femto-¹

from Danish or Norwegian femten fifteen

Example Sentences

Griffith dies and is reborn as Femto, a member of the God Hand, who is undeterred by moral inhibitions.

From Salon

Femto becomes the spearhead of the God Hand’s schemes.

From Salon

Far to the right side of the decimal point—beyond milli, micro, nano, pico, and femto—lives the atto, the metric prefix representing 10-18.

From Science Magazine

His pioneering work came in an area known by the exotic sounding name of femtochemistry, where femto is a prefix used to suggest quantities and time intervals on the order of a millionth of a billionth of those encountered in the everyday world.

From Washington Post

Just as slow-motion photography revealed aspects of common events hidden from the scrutiny of the unaided human senses, “femto” techniques, embodying laser capabilities, gave science new insights into how chemical reactions proceed.

From Washington Post