em quad

noun

1. a square unit of area, one em on each side.
2. a quad having such an area. Compare quad ²( def 1 ).

Word History and Origins

Origin of em quad¹

First recorded in 1870–75

Example Sentences

The thickness of the hair space does not always bear the same proportion to the em quad; in some sizes it is one sixth of the em, in others it may be one eighth or one twelfth.

From Project Gutenberg