To upset the self-possession of; ruffle. See Synonyms at embarrass.(verb-transitive)
To frustrate (plans, for example) by throwing into disorder; disarrange.(verb-transitive)
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.
Use "disconcert" in a sentence
"Some of our findings will irk the deeply religious reader, while others will disconcert the deeply secular."
"See Hot Air for more, including a link to the actual language and a reminder that the Democrats never had any intention of doing anything at all to disconcert trial lawyers."
"A rock, turning under his foot on the edge of the precipice, did not disconcert him."