The phrase "addle the wits" means to confuse or bewilder someone. There are a variety of synonyms for this phrase, including befuddle, perplex, stupefy, confound, bemuse, flummox, bewilder, and disorient. These words all convey the idea of causing someone to be mentally disoriented or unable to think clearly. Adjectives that could describe someone who is "addled" could include confused, muddled, dazed, or discombobulated. These words can be used in a range of situations, from describing the effects of a particularly difficult test, to describing how someone might feel after being given complex instructions.