リーサスMeanings1nounrhesus monkey; rhesus macaquerare termRare term; usually appears in scientific or zoological contexts. In everyday Japanese, アカゲザル (赤毛猿) is far more common.リーサスは実じっ験けん動どう物ぶつとしてよく知しられている。The rhesus monkey is well known as a laboratory animal.