majga experimental gismu

x1 (number/quantity; contextless default: li ma'u .a li no) is the (rest/inertial) mass of x2 (object) in units x3

See also: grake, junta, nonmajga.

In notes:

x1 is massive, x1 has a great mass by standard or relatively to x2 (plural)
x1 is massless/is a massless particle
x1 (object) has charge x2 (number) in units x3 for interaction/of type x4 and in/by/using convention x5