Found 2 items, similar to Em.
English → English (WordNet)
Definition: em
em
n 1: the square of a body of any size of type [syn: 
mutton, 
mut]
2: a linear unit (1/6 inch) used in printing [syn: 
pica em, 
pica]
English → English (gcide)
Definition: Em
Em 
\Em\, n. (Print.)
The portion of a line formerly occupied by the letter m, then
a square type, used as a unit by which to measure the amount
of printed matter on a page; the square of the body of a
type.
[1913 Webster]