1. That confounds, contradicts or confuses
   "The confounding results of the study puzzled the researchers";
   - contradictory

1. Confuse or leave at a loss because of something complex or difficult to understand
   "These questions confound even the experts";
   - confuse, throw, fox, befuddle, fuddle, bedevil, discombobulate [informal], perplex, vex, stick, get, puzzle, mystify, baffle, beat, pose, bewilder, flummox, stupefy, nonplus, gravel, dumbfound
    
2. Mistake one thing for another
   "He confounded the twins";
   - confuse

See also: unsupportive

Type of: affect, bear on, bear upon, impact, misidentify, mistake

Encyclopedia: Confounding