confound

sense 1: be confusing or perplexing to; cause to be unable to think clearly; "These questions confuse even the experts"; "This question completely threw me"; "This question befuddled even the teacher"
confuse throw fox befuddle fuddle bedevil confound discombobulate

sense 2: mistake one thing for another; "you are confusing me with the other candidate"; "I mistook her for the secretary"
mistake confuse confound