Source : Webster's Revised Unabridged Dictionary (1913)

Intrude \In*trude"\, v. i. [L. intrudere, intrusum; pref. in- in
   + trudere to thrust, akin to E. threat. See {Threat}.]
   To thrust one's self in; to come or go in without invitation,
   permission, or welcome; to encroach; to trespass; as, to
   intrude on families at unseasonable hours; to intrude on the
   lands of another.

         Thy wit wants edge And manners, to intrude where I am
         graced.                                  --Shak.

         Some thoughts rise and intrude upon us, while we shun
         them; others fly from us, when we would hold them. --I.
                                                  Watts.

Intrude \In*trude"\, v. t. [imp. & p. p. {Intruded}; p. pr. &
   vb. n. {Intruding}.]
   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.

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

            Why should the worm intrude the maiden bud? --Shak.

   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}.

Source : WordNet®

intrude
     v 1: enter uninvited; "They intruded on our dinner party"; "She
          irrupted into our sitting room" [syn: {irrupt}]
     2: enter unlawfully on someone's property; "Don't trespass on
        my land!" [syn: {trespass}]
     3: thrust oneself in as if by force; "The colors don't intrude
        on the viewer" [syn: {obtrude}]