A sound associated with alternating current which has a frequency a multiple of that of the mains electricity.

plural of left main

(grammar) The verb in a clause with the highest semantic content.

(grammar) A clause that can stand alone syntactically as a complete sentence and contains at least a subject and a verb.

The principal pipe, usually underground, for conveying water to residential and business properties.

(linear algebra) The entries of a square matrix from the top left to the bottom right.

Alternative form of main sequence.

(astronomy) A major grouping of stars represented on a Hertzsprung-Russell diagram by a nearly uniform band of increasing luminosity with increasing surface temperature.

Alternative form of mainsheet

The conduit through which coal gas or natural gas is conveyed to users.