The Collaborative International Dictionary of English v.0.48:

Intercourse \In"ter*course\, n. [Formerly entercourse, OF.
   entrecours commerce, exchange, F. entrecours a reciprocal
   right on neighboring lands, L. intercursus a running between,
   fr. intercurrere to run between. See Inter-, and Course.]
   1. A commingling; intimate connection or dealings between
      persons or nations, as in common affairs and civilities,
      in correspondence or trade; communication; commerce;
      especially, interchange of thought and feeling;
      association; communion.
      [1913 Webster]

            This sweet intercourse
            Of looks and smiles.                  --Milton.
      [1913 Webster]

   2. Same as sexual intercourse.
      [PJC]

   Sexual intercourse, sexual or carnal connection; coition;
      copulation, especially between humans.

   Syn: Communication; connection; commerce; communion;
        fellowship; familiarity; acquaintance.
        [1913 Webster]

WordNet (r) 3.0 (2006):

intercourse
    n 1: communication between individuals [syn: intercourse,
         social intercourse]
    2: the act of sexual procreation between a man and a woman; the
       man's penis is inserted into the woman's vagina and excited
       until orgasm and ejaculation occur [syn: sexual
       intercourse, intercourse, sex act, copulation,
       coitus, coition, sexual congress, congress, sexual
       relation, relation, carnal knowledge]