1. To give instructions to or to direct someone to do something from an a position of authority.
2. To prohibit or to forbid something; that is, to order or to recommend emphatically.
3. To command someone to do something or to behave in a particular way: "We were enjoined to not say anything about the incident."
4. Etymology: from engoinen, from the stem of Old French enjoindre, "to impose (on), to inflict; to subject to; to assign (to)"; from Latin injungere, "to join, to fasten, to attach"; figuratively, "to inflict, to attack, to impose"; from in-, "on" + jungere, "to join".