moo / moue are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
moo: (noun) the sound made by a cow or bull. (verb) make a low noise, characteristic of bovines.
moue: NA
moo: m·UW
moue: NA
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)