la madrastra - stepmother
  el maíz - corn (American English), maize...
  la mortandad - mortality, number of mortalities,...
  la mostaza - mustard
  el murciélago - bat (birdlike mammal)
  el mote - nickname
  la moto - motorcycle, motorbike
  el mirador - scenic viewpoint; enclosed, windowed...
  Marruecos - Morocco
  la memoria - memory, remembrance, academic paper,...
  la miel - honey, molasses, sweetness
  el muslo - thigh, drumstick (of a bird)
  la moneda - coin, currency, money, wealth
  el mondadientes - toothpick
  el melocotón - peach
  el marchito - faded, wilted, shriveled, worn
  la mayonesa, la mahonesa - mayonnaise
  el lagarto - lizard
  la labia - ability to speak persuasively and/or...
  el linde, la linde - boundary, border, dividing line