methane : Idioms & Phrases

• noun a series of non-aromatic saturated hydrocarbons with the general formula CnH(2n+2)
  alkane; paraffin series; alkane series; paraffin.
  

WordNet

• (Chem.), a series of saturated hydrocarbons, of which methane is the first member and type, and (because of their general chemical inertness and indifference) called also the paraffin (little affinity) series. The lightest members are gases, as methane, ethane; intermediate members are liquids, as hexane, heptane, etc. (found in benzine, kerosene, etc.); while the highest members are white, waxy, or fatty solids, as paraffin proper.

Webster 1913