Dic: close in (on someone or something)

• Hitler himself committed suicide as Soviet forces were closing in on Berlin.
• As Parretti walked across the tarmac, fraud officers closed in.
• The dark nights and cold weather are closing in.
• The cops were closing in on the thugs.
• They closed in quietly and trapped the bear.
• My problems are closing in on me.
• I feel trapped. Everything is closing in.

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1. PHRASAL VERB:

If a group of people close in on a person or place, they come nearer and nearer to them and gradually surround them. (= move in)

2. PHRASAL VERB:

When winter or darkness closes in, it arrives. (= descend)

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1. Lit. to move inward on someone or something.

2. Fig. [for threats or negative feelings] to overwhelm or seem to surround someone or something.

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Cf 1. If you are closing on someone or something that you are following, you are getting nearer and nearer to them.

• I was within 15 seconds of the guy in second place and closing on him.

Cf 2. close (someone or something) in (something) :

to contain someone or something in something or some place; to seal someone or something inside something.

• Don't close the bird in such a small cage.
• Don't close me in! Leave the door open.

.... Cobuild, McGraw-Hill Dictionary of American Idioms and Phrasal Verb