Definition of "mass" []

• A unified body of matter with no specific shape: a mass of clay. (noun)
• A grouping of individual parts or elements that compose a unified body of unspecified size or quantity: "Take mankind in mass, and for the most part, they seem a mob of unnecessary duplicates” ( Herman Melville). (noun)
• A large but nonspecific amount or number: a mass of bruises. (noun)
• A lump or aggregate of coherent material: a cancerous mass. (noun)
• The principal part; the majority: the mass of the continent. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "(Force) = (gravitational mass) × (intensity of the gravitational field), where the “gravitational mass” is likewise a characteristic constant for the body."
• "(Force) = (inertial mass) × (acceleration), where the “inertial mass” is a characteristic constant of the accelerated body."
• "The epiglottis is derived from the “central mass, ” and has a third arch element in its oral and upper aspect; the arch value of the “central mass” is doubtful."