verb no object (usually encroach on/encroach upon)

intrude on (a person's territory or a thing considered to be a right):

｟否定的に｠ 【力･権利･時間･効果などを】侵害する, 制限する, 削（そ）ぐ «on, upon»

e.g. rather than encroach on his privacy she might have kept to her room.

advance gradually beyond usual or acceptable limits:

〈物･人が〉 【土地を】(徐々に)侵食する «on, upon, into»

e.g. the sea has encroached all around the coast.

late Middle English (in the sense ‘obtain unlawfully, seize’; formerly also as incroach): from Old French encrochier ‘seize, fasten upon’, from en- ‘in, on’ + crochier (from croc ‘hook’, from Old Norse krókr).