(idiomatic, intransitive) To play a subsidiary or subordinate role to someone or something else.

(computing, Internet) A domain that is immediately subordinate to a top-level domain (whose name appears after it, with a period separating the two).

(informal) conversation overheard from someone talking on a mobile phone

(physics) Newton's observation that the rate of change of the momentum of a body is directly proportional to, and in the same direction as, the net force acting on it.

World War II.

Of or relating to a measurement system that uses the foot as a measure of distance, the pound as a measure of force, and the second as a measure of time. Abbreviations: ft-lb-s, fps, f.p.s.

A unit of mechanical power, equal to that required to raise one pound through a distance of one foot in one second.

The smoke from cigarettes, especially in an enclosed environment, that any person including non-smokers could breathe in.

plural of party of the second part

A system of units used in physics and other sciences, often abbreviated as mks. It is the basis of the SI system of international units.