acetylene
acet.y.lene \*-'set-*l-*n, -*l-, e-n\ \*-.set-*l-'e--nik, -'en-ik\ n : a colorless gaseous hydrocarbon Hc<triple-bond>ch made esp. by the a ction of water on calcium carbide and used chiefly in welding and soldering and in organic synthesis - acet.y.le.nic aj