ACETYLENE

n. ethine, gaseous hydrocarbon used in welding and in chemical manufacture (Chemistry)

Acetylene (systematic name: ethyne) is a hydrocarbon belonging to the group of alkynes. It is considered to be the simplest of all alkynes as it consists of two hydrogen atoms and two carbon atoms. Acetylene is an unsaturated organic compound because its four atoms are triple bonded through a covalent bond.
See more at Wikipedia.org...

Acetylene /acet·y·lene/ HCtbondCH, a colorless, volatile, explosive gas, the simplest alkyne. a·cet·y·lene n. [more]Acetylene - Community and Resources

Noun
1. a colorless flammable gas used chiefly in welding and in organic synthesis
(synonym) ethyne, alkyne
(hypernym) aliphatic compound
(substance-holonym) oxyacetylene

n. acetylene, ethine, gaseous hydrocarbon used in welding and in chemical manufacture (Chemistry)