Snifting valve, a small valve opening into the atmosphere from the cylinder or condenser of a steam engine, to allow the escape of air when the piston makes a stroke; -- so called from the noise made by its action. [ 1913 Webster ]
a. 1. Changing in place, position, or direction; varying; variable; fickle; as, shifting winds; shifting opinions or principles. [ 1913 Webster ]
2. Adapted or used for shifting anything. [ 1913 Webster ]
Shifting backstays (Naut.), temporary stays that have to be let go whenever the vessel tacks or jibes. -- Shifting ballast, ballast which may be moved from one side of a vessel to another as safety requires. -- Shifting center. See Metacenter. -- Shifting locomotive. See Switching engine, under Switch. [ 1913 Webster ]