English

femtomachine

From femto- + machine, by analogy with micromachine, nanomachine, and so on.

Proto-Germanic *fimftehun ‘fifteen’

Old Norse fimmtán ‘fifteen’

Danish femten ‘fifteen’

Doric Greek μᾱχᾰνᾱ́ ‘machine, contrivance (Doric)’

Latin māchina ‘a machine, contrivance’

Middle French machine ‘machine’

Today it means

noun A (hypothetical or fictional) machine on the femto scale; that is, a mechanical device whose size is on the order of the femtometer.

Language periods are conventional ranges, not dates for this word.

Etymograph / femtomachine