The Collaborative International Dictionary of English v.0.48:

Intrude \In*trude"\, v. t. [imp. & p. p. Intruded; p. pr. &
   vb. n. Intruding.]
   [1913 Webster]
   1. To thrust or force (something) in or upon; especially, to
      force (one's self) in without leave or welcome; as, to
      intrude one's presence into a conference; to intrude one's
      opinions upon another.
      [1913 Webster]

   2. To enter by force; to invade. [Obs.]
      [1913 Webster]

            Why should the worm intrude the maiden bud? --Shak.
      [1913 Webster]

   3. (Geol.) The cause to enter or force a way, as into the
      crevices of rocks.

   Syn: To obtrude; encroach; infringe; intrench; trespass. See
        Obtrude.
        [1913 Webster]

WordNet (r) 3.0 (2006):

intruding
    adj 1: projecting inward