1. A numeral or string of numerals that is used for identification
   - number

Type of: positive identification

• undistinguished
• undistorted
• undistributed
• undisturbed
• undiversified
• undividable
• undivided
• undivided interest
• undivided right
• undo
• undoable
• undock
• undocumented
• undoer
• undogmatic
• undogmatical
• undoing
• undomestic
• undomesticated
• undone
• undoubted
• undoubtedly
• undrained
• undramatic
• undramatically