ADJECTIVE (3)

1. (of animals) not recorded with or certified by an official breed association;
- Example: "unregistered dairy cattle"

2. not registered;
- Example: "an unregistered citizen"

3. (a boat or vessel) not furnished with official documents;

The Collaborative International Dictionary of English v.0.48:

Unregistered \Unregistered\
   See registered.

WordNet (r) 3.0 (2006):

unregistered
    adj 1: (of animals) not recorded with or certified by an
           official breed association; "unregistered dairy cattle"
           [ant: registered]
    2: not registered; "an unregistered citizen" [ant: registered]
    3: (a boat or vessel) not furnished with official documents