m.u or mu is an abbreviation that means "Mutual Understanding." It's when two people like each other but won't commit to a relationship.
me and julia aren't together, just m.u.
by kimkikay March 24, 2020
M.U. Mutual Understanding. This meaning can be defined in two ways:

a. 2 people like each other but aren't in a relationship
b. A talking stage between two people who like each other
N: Hey, aren't they a M.U.?
by Rocksssssssssssssssss October 23, 2022
Abbreviated for the phrase, "Mobile Upload." Most commonly used on Facebook. Only those deeply affiliated with Mobile Uploads can use it. "Mupload" is the immature form of M.U.
That's such a cute m.u.! Let's upload it!
by musforeveR!!!! January 26, 2010
1. hayy.. gusto ko tanggalin m.u ko..
2. cant take off my m.u
3.

kris 3:56:45 AM
di ko nagawa mg bura ng m.u ko
by gagongdj December 6, 2010