me·than·o·gen 
(mə-thănə-jən)
(mə-thănə-jən)n.
Any of various anaerobic archaea that produce methane as a metabolic byproduct.
- protodermal
- protogalaxy
- Proto-Germanic
- protogynous
- protogyny
- protohistorian
- protohistoric
- protohistory
- protohuman
- Proto-Indo-European
- protolanguage
- protolithic
- protomartyr
- protomorph
- protomorphic
- proton
- protonema
- protonemal
- protonematal
- protonic
- protonotary
- protonotary
- protonotary apostolic
- proton-proton chain
- proton pump inhibitor