keep (a) close watch on (someone/something)

to guard or follow carefully someone or something.

With an international team keeping close watch on polling stations, voters chose from an array of 12 candidates.

Republicans are warning the president to keep a close watch on spending.

Usage notes: sometimes used in the form keep a watch on:

He wants to keep a watch on who comes and goes from the office.

Related vocabulary: keep an eye out for someone/something

• come clean
• come down in the world
• come down off your high horse
• come down on
• come down on like a ton of bricks
• come down on someone
• come down on someone like a ton of bricks
• come down on something
• come down on the side of
• come down on the side of someone
• come down on the side of something
• come down the pike
• come down to
• come down to earth
• come down to earth with a bang
• That's all you need!
• That's a new one on me!
• that's another story
• that's it
• That's just not cricket!
• that's life
• That's more like it.
• That's my story and I'm sticking to it.
• that's news to
• That's news to me.