What It Scores
BRR is a valid word in the tournament list this site uses. Tile values only, before any premium square: 5 in Scrabble and 6 in Words With Friends. The letters break down as B3 R1 R1.
Longer Words Containing BRR
BRR 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.