megalith

n large stone, esp one erected as (part of) a monument in ancient times 巨石（尤指古代作纪念碑用的）.

medium, medium wave (abbr 缩写 MW), medium-sized, medlar, medley, Medusa, meek, meekly, meekness, meerschaum, meet, meet up with, meet with, meeting, meeting-house, meeting-place, mega-, megacycle, megadeath, megahertz, megalithic, megalomania, megalomaniac, megaphone, megaton, meiosis, melancholia, melancholic, melancholy, melange, melanin, meld, melee, meliorism, mellifluence, mellifluous, mellifluously, mellifluently, mellow, mellowly, mellowness,