The Collaborative International Dictionary of English v.0.48:

Enjoinment \En*join"ment\, n.
   Direction; command; authoritative admonition. [Obs.] --Sir T.
   Browne.
   [1913 Webster]

WordNet (r) 3.0 (2006):

enjoinment
    n 1: (law) a judicial remedy issued in order to prohibit a party
         from doing or continuing to do a certain activity;
         "injunction were formerly obtained by writ but now by a
         judicial order" [syn: injunction, enjoining,
         enjoinment, cease and desist order]