noun

1. a standard or unit of measurement; specif.,
   1. in classical architecture, the diameter, or one half the diameter, of a column at the base of the shaft, used to determine the proportions or the structure
   2. any of several standardized units of measurement used in architectural planning, in the construction of building materials, etc. 4-inch module, 2-foot module
2. ☆
   1. any of a set of units, as cabinets, designed to be arranged or joined in a variety of ways
   2. a detachable section, compartment, or unit with a specific purpose or function, as in a spacecraft
   3. Electronics a compact assembly that is a component of a larger unit

Etymology: Fr module < L modulus, dim. of modus: see mode