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.

Source: Webster's Revised Unabridged Dictionary (1913)
 

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: Webster's Revised Unabridged Dictionary (1913)