To collide or strike: Sound waves impinge on the eardrum.
To encroach; trespass: Do not impinge on my privacy.
To encroach upon: "One of a democratic government's continuing challenges is finding a way to protect . . . secrets without impinging the liberties that democracy exists to protect” ( Christian Science Monitor).
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.