from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Another side of oneself; a second self.
- n. An intimate friend or a constant companion.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Somebody's alternate personality or persona; another self.
- n. A very close and intimate friend.
from The Century Dictionary and Cyclopedia
- Second self; another self; counterpart; double.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a very close and trusted friend who seems almost a part of yourself
Latin : alter, other + ego, I, self.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Latin "other self", which is a translation of Zeno's Citium "allos ego"  (Wiktionary)
Sorry, no example sentences found.