Definitions:
a large body of matter with no definite shape

a large number of people or objects crowded together

the majority of

the quantity of matter which a body contains, as measured by its acceleration under a given force or by the force exerted on it by a gravitational field

involving or affecting large numbers of people or things

assemble or cause to assemble into a single body or mass

the celebration of the christian eucharist, especially in the roman catholic church