Allan Wood's definitions

Xum

An abbreviation of the word "Excuse Me." It gets its sound from combining the "X" sound in "Ex," the "U" sound from "c-UE-se" and of course the "M" from "Me."

It can also be used as a question, as in "Pardon me?"

Example 1:
*Someone sneezes*
Someone: "Xum."

Example 2:
A: "Does it smell like Up Dog in here?"
B: "Xum?"

by Allan Wood March 10, 2008