encroach (up)on (something)
To approach or cross a literal or figurative boundary. That fool next door totally encroached upon my land when he built his new fence. I'm sorry, I didn't mean to encroach on your authority by assigning work to your interns.
See also: encroach
encroach (up)on someone or something
to infringe or trespass on someone or something; to move into the space belonging to someone or something. (Upon is formal and less commonly used than on.) I did not mean to encroach upon your property. I need lots of space. Don't encroach on me.
encroach onor encroach upon
To advance or extend toward or into something beyond its proper or former limits: The weeds in my neighbor's yard are encroaching on my lawn. At the edge of the village, the desert encroaches upon grassland.