(en) noun
1. The name of the fourteenth letter in the English alphabet, written N or noun
2. Printing A space half the width of an em.

Forming transitive verbs:
1. (from nouns) To cover or surround with; to place into or upon: encircle.
2. (from adjectives and nouns) To make; cause to be or to resemble: enable, enfeeble.
3. (from verbs) Often with simple intensive force, or used to form transitive verbs from intransitives: enact, encompass. Also, em- before b, p, and sometimes m, as in embark. Many words in en- have variant forms in in- because of the confusion between Old French en-, Latin in-, and native English in-. Compare IN-² and IN-³. [<OF <L in- <in in, into]

In, into; on: endemic. Also: el- before l, as in ellipse; em- before b, m, p, ph, as in embolism, empathy; er- before r, as in errhine. [<Gk. en- <en in, into]

Forming verbs:
1. (from adjectives) Cause to be; become: deepen, harden.
2. (from nouns) Cause to have; gain: hearten, strengthen. [OE -nian]