In typography, a unit of measurement exactly one-half as wide as, and as high as, the point size being set. In 12-point type, the en is 6 points wide and 12 points high. An en or en space is also defined as a fixed space having a width half as wide as an em. See Fixed Space. An en dash is a dash as wide as the en for that particular typeface and type size. See Dashes.