# thick as thieves

> English word · Adjective

## Definitions
1. Intimate, close-knit, tight.

## Etymology
From thick (“friendly, intimate”), first attested in 1827 as "thick as two thieves".

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/thick-as-thieves