Mo

The word “Mo” means informal shortening of "moment"; used in phrases like "half a mo" or "wait a mo.". In plain terms, casual short form of "moment" (wait a mo) or, separately, slang for "moustache.".

“Mo” is pronounced MOH (/ˈməʊ/ in IPA).

Here is “Mo” used in a sentence: “Hang on a mo, I'll be right there.”

Depending on how it is used, “Mo” can be an adverb and a noun.

“Mo” is a fairly common word in modern English.

“Mo” has 2 distinct senses listed in this dictionary. The most common is: informal shortening of "moment"; used in phrases like "half a mo" or "wait a mo.".

Both are informal ways of asking for a very short amount of time. Mo is a clipping of "moment" and is heard chiefly in British English, while sec clips "second" and is common everywhere. In practice they are interchangeable: "give me a mo" and "give me a sec" mean the same thing.

Mo is simply an informal shortening of "moustache," used chiefly in Australian and British English. You might hear someone say a man is "growing a mo" for charity.

No — both senses of mo are informal. In formal writing, use "moment" for the time sense and "moustache" for the facial-hair sense; keep mo for casual speech, texts, and chatty writing.