1To tie, fasten, or tighten something (e.g., a knot, belt, screw); to make something secure or tight.
出かける前にネクタイをきちんと締めてください。
Please fasten your tie properly before going out.
棚板のネジをドライバーでしっかり締める。
Tighten the shelf screws firmly with a screwdriver.
シートベルトをしっかり締めてください。
Please fasten your seatbelt securely.
2To put on or wear items like a necktie, belt, or obi (i.e., to fasten/bind clothing accessories around oneself).
今日は礼服を着てネクタイを締める日だ。
Today is the day to wear formal clothes and a tie.
浴衣の帯を上手に締められるようになりたい。
I want to learn to tie a yukata obi well.
ベルトを少しきつく締めてください。
Please tighten the belt a little.
3To close out or total up accounts/figures; to finalize a tabulation (often written as 〆る).
月末になったので帳簿を締める作業を始めた。
It's the end of the month, so I started closing the books.
今日の売上を締めて報告してください。
Please total today's sales and report them.
会議で議事録をまとめて締める。
Wrap up the meeting by summarizing the minutes.
4To be strict with someone; to tighten discipline or control someone’s behavior.
監督は選手たちを締めて練習の集中を促した。
The coach got tough with the players to encourage focus in practice.
親は子どもの生活態度を締める必要がある。
Parents need to be strict about their child's lifestyle habits.
5To economize or cut down on spending; to tighten one's budget.
赤字が出たので今月は家計を締めることにした。
Because of a deficit, we decided to tighten the household budget this month.
ボーナスが減ったから外食を少し締めよう。
Since bonuses were reduced, let's cut back on eating out a bit.
6To cure or marinate (often with vinegar/salt) to preserve or flavor food (e.g., shime-saba).
今夜はしめ鯖を作るために鯖を酢で締める予定だ。
Tonight I'm going to cure mackerel with vinegar to make shime-saba.
魚を軽く塩で締めてから漬け込む。
Lightly cure the fish with salt before marinating it.
7To dispatch/kill (fish, poultry, etc.), often referring to methods like firming the animal or bleeding it out for processing.
漁師は釣った魚をすぐに締めて氷で冷やした。
The fisherman immediately dispatched the caught fish and chilled it on ice.
料理人は魚を締めてから刺身にする。
The chef prepares the fish (dispatches/bleeds it) before making sashimi.
8Colloquial: to pressure, crack down on, or physically/emotionally clamp down on someone; often written シメる in katakana and can imply violent or strong coercion.
会社で不正が見つかり、社長が関係者をシメたという噂がある。
There are rumors that after fraud was discovered at the company, the president cracked down on those involved.
バイト先でミスを連発したら先輩にシメられた。
Because I kept making mistakes at my part-time job, the senior scolded/pressured me.