Logical Unit Number
(LUN) A 3-bit identifier used on a SCSI bus to distinguish between up to eight devices (logical units) with the same SCSI ID.
Last updated: 1999-02-11
Logical Unit 6.2 ♦ Logical Unit Number ♦ logic bomb ♦ Logic Design Language
Try this search on Wikipedia, Wiktionary, Google, OneLook.