.... (Arch.) An apophyge. 6. Leakage or outflow, as of steam or a liquid. 7. (Elec.) Leakage or loss of currents from the conducting wires, caused by defective insulation. _____ pipe (Steam Boilers), a pipe for carrying away steam that _____s through a safety valve. -- _____ valve (Steam Engine), a relief valve; a safety valve. See under Relief, and Safety. -- _____ wheel (...