noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   A paper size, (1.87"-2.5" x 2.5"-3.125"), one sixty-fourth of a standard uncut flat sheet.
2. 2
   A book size, (1.87"-2.5" x 2.5"-3.125"), corresponding to the paper size.

Synonyms

All synonyms

64mo64ºsixty-fourmoboxcarsdozeneleven

Etymology

From Latin ablatives of sexāgēsimus (“sixtieth”) and quartus (“fourth”).

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