bi·o·gas 
(bīō-găs′)
(bīō-găs′)n.
A mixture of methane and carbon dioxide produced by bacterial degradation of organic matter and used as a fuel.
- septendecillionth
- septennial
- septennially
- septentrion
- septentrional
- septet
- septette
- septic
- septicemia
- septicemic
- septicidal
- septicidally
- septicity
- septic shock
- septic sore throat
- septic tank
- septifragal
- septifragally
- septilateral
- septillion
- septillionth
- septuagenarian
- Septuagesima
- Septuagint
- Septuagintal