one part of a large system or organization.

He was just a small cog in the large wheel of organised crime.

This warehouse is an important cog in our distribution machine.

• the woman in the street
• the woman of dreams
• the woman of your dreams
• the woman on the Clapham omnibus
• the woman on the street
• the wooden spoon
• the works
• the world and his wife
• the world is oyster
• the world is your oyster
• the worm has turned.
• the worse for wear
• the worst-case scenario
• the worst of both worlds
• the writing is on the wall
• the writing on the wall
• the wrong side of the tracks
• They broke the mould when they made someone.
• They broke the mould when they made something.
• They can whistle for it!
• thick skin
• thick-skinned
• thin end of the wedge
• thing is
• thing of the past