bulk
1.
2.
3. The major portion or greater part: "The great bulk of necessary work can never be anything but painful" (Bertrand Russell).
4. See fiber.
5. Thickness of paper or cardboard in relation to weight.
6. Abbr. blk. Nautical. A ship's cargo.
verb
bulked, bulking, bulks
3.
adjective
Being large in mass, quantity, or volume: a bulk buy; a bulk mailing.
in bulk
[Middle English, perhaps partly alteration of bouk, belly, trunk of the body (from Old English būc) and partly from Old Norse bulki, cargo, heap.]