to thrust or bring in without invitation, permission, or welcome.

Geology . to thrust or force into.

to install (a cleric) in a church contrary to the wishes of its members.

to thrust oneself without permission or welcome

to intrude upon their privacy.

noun

burglar , criminal , gate-crasher , infiltrator , interferer , interloper , interrupter , invader , meddler , nuisance , obtruder , prowler , raider , snooper , squatter , thief , trespasser