serial number 
noun
An identification number showing the position of a printed or manufactured item in a series: every bike has a serial number on it...
- US intelligence has recorded their serial numbers to identify their source.
- The serial numbers are printed on adhesive strips, so I put the strip on the case.
- They were trying to see if they could identify him by the serial number on his gun.
- absolute discharge
- absolute drought
- absolute error
- absolute height
- absolute humidity
- absolute idealism
- absolutely
- absolute magnitude
- absolute majority
- absolute monarch
- absolute monarchy
- absolute music
- absolute musician
- absoluteness
- absolute pardon
- absolute pitch
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- absolute privilege
- absolute scale
- absolute state
- absolute superlative
- absolute temperature
- absolute temperature scale
- absolute title
- absolute unit