Token

The means used to confirm the identity of a user, processor, or device (e.g., user password or token). 

See NIST SP 800-53 Rev. 4 under Authenticator for more information. 
   
A portable, user-controlled, physical device (e.g., smart card or memory stick) used to store cryptographic information and possibly also perform cryptographic functions. 

See NIST SP 800-57 Part 2 Rev.1 under Token for more information. 
 
Something the claimant possesses and controls (typically a cryptographic module or password) that is used to authenticate the claimant’s identity. In previous editions of SP 800-63, this was referred to as a token. 

See the following under Authenticator for more information:
NIST.SP.800-63-3.
NIST SP 1800-17b.
NIST SP 1800-17c.

See NIST SP 800-12 Rev. 1 under Token NIST SP 800-63-2 for more information.
 
A physical object a user possesses and controls that is used to authenticate the user’s identity. 

See NISTIR 7711 under Token for more information.