(mechanical) A cock connected with four pipes or ports, and having two or more passages in the plug, by which the adjacent pipes or ports may be made to communicate; formerly used as a valve in the steam engine, and for various other purposes.

(US, electricity): intermediate switch.

The four-way valve or four-way cock is a fluid control valve whose body has four ports equally spaced round the valve chamber and the plug has two passages to connect adjacent ports.

The Four-Way Test of the things we think, say or do is a test used by Rotarians world-wide as a moral code for personal and business relationships.