Blood is thicker than water.

What it means

Ties of family outrank ties of friendship, affiliation or convenience, especially when something is at stake. Usually said approvingly of someone who turned up for a relative, occasionally with resignation about someone who took a family member’s side against the evidence.

Where it comes from

The idea is medieval: a version appears in the German beast epic “Reinhart Fuchs” around 1180, and the English priest John Lydgate wrote in 1412 that blood will always draw to blood. A widely shared claim that the “original” was “the blood of the covenant is thicker than the water of the womb”, and meant the opposite, has no historical support — it is a modern invention, not a lost original.

Example sentences

• “He gave his brother the job over a better candidate. Blood is thicker than water.”
• “They had not spoken in years, and she still paid his rent — blood is thicker than water.”
• “Do not expect her to testify against her own son; blood is thicker than water.”

When it fits — and when it does not

Warm about loyalty, critical about nepotism — the context does all the work. If you have heard the “covenant” version, do not repeat it as fact.

Similar phrases

• Charity begins at home.
• Family comes first.