M

Mailchimp

It’s Mailchimp, not MailChimp. It used to be MailChimp, but they changed it to Mailchimp.

Mary Celeste

Not Marie Celeste.

master’s [degree]

Takes apostrophe-s and is not capitalised.

media, medium, mediums

Strictly speaking, media (as in mass media, social media, etc.) is a plural. It’s the plural of medium. It’s now widely used as a singular word, like data. It’s best to avoid the plural form mediums unless you’re referring to spiritualists or psychics.

metadata

One word.

meta tag

Two words.

microsite

One word.

Middle East

Initial cap both words.

Midlands

  • West Midlands – initial cap both words because it’s a county.
  • east Midlands – lower case E because it’s not a county or administrative district.
  • East Midlands Airport – initial cap every word because it’s a proper noun.

minuscule

Not miniscule.

moot, mute

Sometimes people talk of a “mute point” or they talk of an idea being “muted”. They mean moot, and mooted.

  • Mute means silent, or refraining from speech, or not expressed in speech; and in this day and age the word is commonly used in the sense of muting your microphone in a video call. There is also a kind of swan called a mute swan (so called because it’s less vocal than other species of swan).
  • Moot is an adjective meaning debatable or questionable. It’s also a verb meaning to raise a topic for discussion or suggest an idea. (“A business rate rise for higher-value properties is being mooted”.)