Encyclopedias, Almanacs, Transcripts, and Maps
- mongolism
- Mongooses and Fossa (Herpestidae)
- Monitors, Goannas, and Earless Monitors (Varanidae)
- Monk, Thelonious Sphere
- Monkey-Wrenching
- Monkeys
- Mono Lake
- Monoblastozoa (Salinella)
- Monogenea (Monogeneans)
- monomer
- Monoplacophora (Monoplacophorans)
- Monotremata (Monotremes)
- monstera
- Montagu, Lily
- months of the year
- Montreal Protocol on Substances That Deplete the Ozone Layer (1987)
- Moody, Dwight L.
- Moore, George Foot
- moorhen
- Morality and Religion