Thick as Thieves – Meaning, Origin & Usage

As an idiom, the phrase “thick as thieves” can be hard to understand if you’re generally unfamiliar with English idioms. But the good news is that this article is going to explain it all…

We will cover the meaning, origins and usage of the phrase, complete with a few examples. We will also briefly discuss references to it in literature and the media, before going into comparable synonymous words and phrases. Let’s get to it!

What does the phrase “thick as thieves” mean?

The idiom “thick as thieves” is used to refer to two or more people who are very close and are likely to share their secrets with one another.

The historical origins of the phrase “thick as thieves”

The phrase “thick as thieves” dates back to the 1800s, when it was first used in the criminal underworld of London, England. During tihis time, thieves would work very closely together, sharing secrets and information, and forming tight alliances, leading to the comparison of their closeness to the thickness of a physical object. 

This led to the use of the term to describe any very close friendship or alliance, and today its use is no longer limited to closeness in relation to criminal activity.

How to use the phrase “thick as thieves”, with examples

Here are some examples of the phrase in use in everyday conversation:

• They may be non-identical, but those twins are joined at the hip – they’re thick as thieves.
• Those two never leave each other’s sides, they’re as thick as thieves.
• They won’t stop talking, those two. Definitely thick as thieves if you ask me.
• We haven’t seen each other for 10 years, but we’ve picked up just as we’ve left off – thick as thieves, the two of us.

References to the phrase “thick as thieves” in literature

Here are some examples of the phrase being used in classical literature:

In The Catcher in the Rye by J.D. Salinger, the protagonist Holden Caulfield often describes his relationship with his younger sibling, Phoebe, as being ‘thick as thieves,’ sharing a deep bond and understanding.

Similarly, in The Great Gatsby” by F. Scott Fitzgerald, Tom and Myrtle, were already ‘thick as thieves’ in their secret affair.

Then in To Kill a Mockingbird” by Harper Lee, Scout and Dill were described as being ‘thick as thieves’ throughout the summer

Similar and alternative sayings synonymous with the phrase “thick as thieves” 

Here are some alternative sayings that can often be used in place of “thick as thieves”:

• Very close
• Inseparable
• Two peas in a pod
• Familiar
• Intimate
• Chummy
• Tight
• Thick
• BBFs
• Best friends
• Best mates
• Bosom Buddies

Final word

In short, the phrase “thick as thieves” is used to refer to two or more people who are very close and are likely to share their secrets with one another. It is derived from the behaviour of thieves in 19th century London, England. However, today the term is used to refer to closely only and not necessarily any criminal behaviour.