moo

As a pronoun moo

is we.

As a noun shoe is

a protective covering for the foot, with a bottom part composed of thick leather or plastic sole and often a thicker heel, and a softer upper part made of leather or synthetic material shoes generally do not extend above the ankle, as opposed to boots, which do.

As a verb shoe is

to put shoes on one's feet.

As a pronoun moo is

we.

As nouns the difference between moo and mooer

is that moo is the characteristic sound made by a cow or bull while mooer is one who moos.

As a verb moo

is of a cow or bull, to make its characteristic lowing sound.

As an interjection moo

is the characteristic sound made by a cow or bull.

As an initialism MOO

is matter of opinion.