1. xo - Noun
2. xo - Adjective
xo
Alternative form of xoxo (an abbreviation for hugs and kisses, usually placed at the end of a letter.)
XO (not comparable)
Initialism of extra old; a grade of premium cognac, that has been aged in barrels for more than 6.5 years.
XO (plural XOs)
(military, nautical) Initialism of executive officer.