"Dear John" is a letter that ends a relationship. "Dear" is a term of endearment, but it is also a formal opening. It comes from the Old English "deore," meaning precious or costly. It is used at the start of letters, in speech between loved ones, and as a polite address to strangers. A teacher might say, "Dear, please sit down." A partner might say, "Dear, I'm home."

The word is flexible. It can be warm or distant. "Dear Sir" is formal. "My dear" is intimate. "Dearie" is a diminutive, often used by older women. The tone shifts with the relationship. Dear is not as passionate as "darling" or as casual as "honey." It is steady. It is reliable.

Common uses

• Letter opening: Dear Mr. Smith, Dear Mom.
• Term of endearment: Yes, dear.
• Polite address: Dear, can I help you?
• Expression of concern: Oh dear, that's a problem.

Dear is also an exclamation. "Oh dear" means mild dismay. "Dear me" is surprise. The word carries a gentle tone even when it is not about love. It is a small word with a long reach. It has been in English for over a thousand years. It is not going anywhere.