The two new coworkers are as thick as thieves.
thick as thieves
idiomIntimate, close-knit, tight.
Origin
first recorded 19th c.From thick (“friendly, intimate”), first attested in 1827 as "thick as two thieves".
Ever since they started working on the project together, those two have been as thick as thieves.
Despite their vastly different backgrounds, the two conspirators became as thick as thieves while planning their daring escape from the city.
- 01
come thick and fast
To arrive rapidly in large groups.
- 02
lay it on thick
To exaggerate or overstate a feeling or emotion.
- 03
thick and thin
Both good and bad times.
- 04
thick and threefold
In quick succession, or in great numbers.
- 05
thick end
Most; the greater part (of an amount of money).
- 06
thick of things
A central or major role in a situation; a position in which one is surrounded by or very involved in complex, changing events.
- 07
thick skin
Ability to take criticism or harsh behavior without being easily offended.
- 08
through thick and thin
Through all (especially grim, rough and difficult) conditions; in all weathers.