What It Scores
BUB is a valid word in the tournament list this site uses. Tile values only, before any premium square: 7 in Scrabble and 10 in Words With Friends. The letters break down as B3 U1 B3.
Longer Words Containing BUB
BUB appears inside each of these, which is what makes it worth knowing as a hook.
Next: the Word Unscrambler for any letters at all, and the two and three letter lists. Full entry and definition at Merriam-Webster.