godan verb (-ru), intransitive verb
Only when written 閉まる
Intransitive: a door, window, lid, shop, etc. closes or is in a closed state. Usually written 閉まる for this sense.
風でドアが閉まった。
The door closed because of the wind.
この店は八時に閉まる。
This shop closes at eight.
godan verb (-ru), intransitive verb
be firm; be well-knit; look toned
Only when written 締まる
Used of a body, face, expression, or form that looks firm, compact, or well put together. The common spelling is 締まる, often in the form 締まった.
彼は締まった体つきをしている。
He has a firm, well-toned build.
godan verb (-ru), intransitive verb
be locked
Only when written 閉まる
Used when a lock, door, or entrance is secured. 鍵がかかる is also a very common way to say that something is locked.
裏口の鍵はもう閉まっています。
The back door is already locked.
godan verb (-ru), intransitive verb
tighten; be tightened; be tight
Only when written 締まる / 緊まる
Intransitive: a screw, belt, knot, tap, etc. becomes tight or is in a tightened state. Written 締まる in ordinary modern use.
このネジはまだしっかり締まっていない。
This screw is not tightened properly yet.
ベルトがきつく締まっている。
The belt is fastened tightly.
godan verb (-ru), intransitive verb
become sober; become tense; brace oneself
Only when written 締まる / 緊まる
Mental or emotional use, often in set phrases such as 身が締まる思い, meaning that one feels sobered, braced, or made tense by a serious situation.
先生の厳しい言葉に身が締まる思いがした。
The teacher's stern words made me feel sobered and braced.