noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   US spelling of femtometre. US, alt-of
2. 2
   a metric unit of length equal to one quadrillionth of a meter wordnet

Synonyms

All synonyms

femtometrefermi

Etymology

From femto- + meter.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.