1. Size, mass, or volume, especially when very large.
a. A distinct mass or portion of matter, especially a large one: the dark bulk of buildings against the sky.
b. The body of a human, especially when large or muscular.
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. A ship's cargo.
v. bulked, bulk·ing, bulks
1. To be or appear to be massive in terms of size, volume, or importance; loom: Safety considerations bulked large during development of the new spacecraft.
2. To grow or increase in size or importance.
3. To cohere or form a mass: Certain paper bulks well.
1. To cause to swell or expand.
2. To cause to cohere or form a mass.
Being large in mass, quantity, or volume: a bulk buy; a bulk mailing.
To gain weight by gaining muscle: dietary supplements that helped the weightlifters bulk up.
1. Unpackaged; loose.
2. In large numbers, amounts, or volume.
[Middle English, perhaps partly alteration of bouk, belly, trunk of the body (from Old English būc) and partly from Old Norse bulki, cargo, heap; see bhel-2 in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.