impersonal pronoun 
noun
The pronoun it when used without definite reference or antecedent, as in it was snowing and it seems hard to believe.
- Marston Moor, Battle of
- marsupial
- marsupial bone
- marsupial cat
- marsupial frog
- Marsupialia
- marsupialise
- marsupialization
- marsupialize
- marsupial lion
- marsupial mole
- marsupial mouse
- marsupial rat
- marsupial wolf
- marsupium
- Marsyas
- mart
- Martaban, Gulf of
- martabani
- martagon lily
- Martavaan
- Martel, Charles
- martellato
- Martello
- Martello tower