still waters run deep
Meaning
A calm or quiet person may have deep thoughts, strong feelings, or hidden abilities.
Origin
From the observation that slow-moving or calm-looking water can be deepest and most dangerous. A proverb recorded in Latin and later popularized in English (notably in the 16th century, including Shakespeare).
Notes
Used as a proverb about people: quiet doesn’t mean shallow. Can be admiring or cautionary. Slightly proverbial/formal tone.
Examples
-
Don’t underestimate Maya—she barely speaks in meetings, but still waters run deep.
-
He seems quiet at first, yet still waters run deep once you get to know him.
-
The new intern keeps to herself, and I suspect still waters run deep.
-
Everyone thought Mr. Tanaka was shy, but still waters run deep; he’s an expert negotiator.
-
She doesn’t post much online, but still waters run deep—she’s been building a successful business for years.
Grammar & Usage Notes
Fixed proverb; usually used as a standalone sentence. Variants exist (e.g., “still waters run deepest”), but “still waters run deep” is the standard form.
Synonyms
- there’s more than meets the eye
- beware of a quiet man
Antonyms
- what you see is what you get
- open book