em

The word “em” means a typographic unit of measurement equal to the point size of the current font, used to size text and spacing. In plain terms, most commonly seen today as a unit in web and print design (like the "em dash" or font sizing in "em" units), or as a hesitation sound in speech.

“Em” is pronounced EHM (/ˈɛm/ in IPA).

Here is “em” used in a sentence: “The designer set the line height to 1.5 em.”

Depending on how it is used, “em” can be a noun and an interjection.

“Em” is a fairly common word in modern English.

“Em” has 3 distinct senses listed in this dictionary. The most common is: a typographic unit of measurement equal to the point size of the current font, used to size text and spacing.

Both are typographic units based on the font's point size. An em equals the full point size; an en is exactly half an em. This carries into punctuation: the em dash (—) is twice the width of the shorter en dash (–), and they serve different purposes.

An em dash (—) marks a strong break in a sentence — like this — setting off an interruption, an aside, or an emphatic addition. It can replace commas, parentheses, or a colon. It takes its name from the em, being roughly one em wide in traditional type.

One em equals the current font's point size, so in 12-point text an em measures 12 points. Because it scales with the type size, the em is a relative unit: designers use it to set margins, indents, and spacing that stay proportional as text grows or shrinks.