early 14c., "an attack of fever," from Old French acces "onslaught, attack; onset (of an illness)" (14c.), from Latin accessus "a coming to, an approach," noun use of past participle of accedere "approach" (see accede). The later senses are directly from Latin. Meaning "an entrance" is from c.1600. Meaning "habit or power of getting into the presence of (someone or something)" is from late 14c.