Chunk (noun)

1. A large, thick piece of something, often of irregular shape.
2. A substantial amount of something.

Origin:

From middle english chonke, from old english cunc ("lump"), from proto-germanic *kunkaz (compare dutch konk, german kunken, danish kunken), from proto-indo-european *genug- ("to press, squeeze, knea.d")

Examples:

1. He broke the chocolate bar into chunks.
2. The rock was in chunks after the explosion.
3. She took a chunk of bread from the loaf.
4. The chunk of ice had to be chipped away.
5. The chunk of cheese was big enough for three people.