intruder:
(plural: ‘intruders‘; pronunciation: the letter ‘i’ rhymes with the letter ‘i’ in “ink”, and the letters ‘tru’ rhyme with the word ‘true’ — for the right pronunciation, please click here)

an intruder (L) trying to force entry into a house & the owner (R) trying to stop him
a person who goes to a place, such as a meeting, house, party or some place where people without permission are not allowed, especially by force or secretly as a thief;
a trespasser; an interloper; a burglar,

an intruder being chased away by the security
When he heard some noise in the middle of the night, Joe turned down his TV and looked out of his window and on seeing an intruder trying to force open the back door of his kitchen, he immediately turned on all the lights and called for help.
The menace of intruders has become so common place in our district that even children at schools are given special drills as to how to act when they notice any strangers and intruders making a forced entry into their homes or their classrooms.
As there have been more and more cases of intruders and burglars breaking into houses and other buildings and killing the rightful occupants when resisted, the justice department has come up with a new law that gives the rightful owners of the broken into places the right to take extreme physical action, including killing the intruders in self-defence!
