in vivoin vivo /ɪn ˈviːvəʊ $ -voʊ/ adjective 
technical taking place in the body—in vivo adverb
technical taking place in the body—in vivo adverb- martyred
- marvel
- marvellous
- marvellously
- Marvin, Lee
- Marx Brothers
- Marxism
- Marxism-Leninism
- Marxist
- Marxist-Leninist
- Marx, Karl
- Mary
- Mary had a Little Lamb
- Mary II
- Mary I, Queen
- Maryland
- Mary Magdalene, Saint
- Mary, Mary, Quite Contrary
- Mary Poppins
- Mary Quant
- Mary Queen of Scots
- Mary Rose, The
- marzipan
- Masai
- masc.