The “O’” in “o’clock” actually comes from a contraction of an old English phrase.
🕰️ What it really stands for
“O’clock” = “of the clock”
So:
- 5 o’clock = “five of the clock”
- 8 o’clock = “eight of the clock”
📜 Where it comes from
The phrase developed in Middle English when people needed a way to distinguish:
- time told by a clock, vs
- time estimated by natural signs (sun position, etc.)
Over time:
- “of the clock” → “o’ the clock” → “o’clock”
🧠 Why the apostrophe?
The apostrophe in o’clock marks the missing letters from:
- “of” and “the”
So it’s a shortened form, not a standalone word.
⚖️ Bottom line
The “O” in “o’clock” doesn’t stand for a modern word—it’s a historical contraction meaning “of the clock.”
If you want, I can also explain other common English contractions (like “won’t,” “ain’t,” or “don’t”) and where they originally came from.