Wordnet 3.0
NOUN (1)
1. 
 a code (a series of characters or digits) that must be entered in some way (typed or dialed or spoken) to get the use of something (a telephone line or a computer or a local area network etc.); 
[syn: access, access code]
WordNet (r) 3.0 (2006):
access code
    n 1: a code (a series of characters or digits) that must be
         entered in some way (typed or dialed or spoken) to get the
         use of something (a telephone line or a computer or a local
         area network etc.) [syn: access, access code]