Yes, clump is a Scrabble word!

Verb

1. Make or move along with a sound as of a horse's hooves striking the ground

2. Come together as in a cluster or flock

3. Walk clumsily

4. Gather or cause to gather into a cluster

Noun

1. A grouping of a number of similar things

2. A compact mass

3. A heavy dull sound (as made by impact of heavy objects)