(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.

plural of gas main

plural of main line

Alternative spelling of mainline