What It Scores
GLOOP is a valid word in the tournament list this site uses. Tile values only, before any premium square: 8 in Scrabble and 10 in Words With Friends. The letters break down as G2 L1 O1 O1 P3.
Words Made From The Letters In GLOOP
20 shorter words come out of these tiles. On a board that matters more than the long play, because a short word on a premium square often beats a long one on plain squares.
4 letter words (9)
3 letter words (6)
2 letter words (5)
Longer Words Containing GLOOP
GLOOP appears inside each of these, which is what makes it worth knowing as a hook.
Next: the Word Unscrambler for any letters at all. Full entry and definition at Merriam-Webster.