Weights Held in the Hold of a Ship for Stability
Puzzle 10 of Justin Timberlake Piece of Cake Pack
Question is: Weights Held in the Hold of a Ship for Stability
and the answer is: BALLAST
Word Meaning:
BALLAST — (nautical) Heavy material that is placed in the hold of a ship (or in the gondola of a balloon), to provide stability.
Definitions from Wiktionary.