Probably because of its origin in French (vague, 16th century) and Latin (vagus). In Latin "us" is a common suffix.
Anglo-Saxon (old english) and Norse (viking) words do not have such characteristics, but many Norman French borrow words (after 1066) have them, due to the Latin origin of French.
That's awful vague.
A word that starts with U and ends with G: understanding.
Chug is a one syllable word with three phonemes: ch/u/g.
B-U-G spells the word bug.
guru
G Word - 2008 Wood U Recycle was released on: USA: 29 September 2008
B-U-G spells the word bug.
There are no words that contain all of those letters.
The word "glue" has three phonemes: /g/, /l/, /u/.
disguise
ArgusSugar
Luxury is what jumps out at me, but that leaves the extra letters of "i u i". I don't think one word would use ALL the letters you gave!