The Collaborative International Dictionary of English v.0.48:

Promiscuous \Pro*mis"cu*ous\, a. [L. promiscuus; pro before, in
   place of, for + miscere to mix. See Mix. ]
   [1913 Webster]
   1. Consisting of individuals united in a body or mass without
      order; mingled; confused; undistinguished; as, a
      promiscuous crowd or mass.
      [1913 Webster]

            A wild, where weeds and flowers promiscuous shoot.
                                                  --Pope.
      [1913 Webster]

   2. Distributed or applied without order or discrimination;
      not restricted to an individual; common; indiscriminate;
      as, promiscuous love or intercourse.
      [1913 Webster]

WordNet (r) 3.0 (2006):

promiscuous
    adj 1: not selective of a single class or person; "Clinton was
           criticized for his promiscuous solicitation of campaign
           money"
    2: casual and unrestrained in sexual behavior; "her easy
       virtue"; "he was told to avoid loose (or light) women";
       "wanton behavior" [syn: easy, light, loose,
       promiscuous, sluttish, wanton]