ねじ（ねじ、neji）
- screw

The Japanese word ねじ ねじ refers to a screw. It's a type of fastener, typically a metal rod with a helical ridge (thread) used to join things together by rotating it, which then digs into the material. The word ねじ ねじ can also broadly refer to anything that is twisted or screwed.

⚫︎ 木（き）に ねじ を 締（し）める。 Translation: I screw the screw into the wood. ⚫︎ この ねじ は 緩（ゆる）んでいる。 Translation: This screw is loose. ⚫︎ 機械（きかい）の ねじ が 外（はず）れた。 Translation: The screw came off the machine.

You use ねじ ねじ in conversations when referring to screws, bolts, or the action of screwing something. It’s a common word used in construction, mechanics, and everyday situations where fastening is involved. When you're talking about fastening something with a screw, you might use verbs like 締（し）める (to tighten), 回（まわ）す (to turn/rotate), or 外（はず）す (to remove).

⚫︎ ねじ ねじ is primarily written in hiragana. ⚫︎ The kanji for ねじ ねじ is 螺. ⚫︎ The kanji is less commonly used than hiragana. ⚫︎ There are no significant variations in the okurigana.

⚫︎ ビス (ビス) - This is a loanword from "vise" (a type of screw). ⚫︎ ボルト (ボルト) - This is a loanword from "bolt". It often refers to larger screws used with nuts.

While there isn't a direct antonym for ねじ ねじ, words related to loosening or separating could be considered opposite actions, such as: ⚫︎ 緩（ゆる）める (to loosen) ⚫︎ 外（はず）す (to remove/take off)

ドライバー で ねじ を 回（まわ）して 固定（こてい）する。 ・Translation: I turn the screw with a screwdriver to fix it. ・Explanation: This sentence explains how to use a screwdriver to tighten the screw and secure something.

この ねじ は サイズ が 小（ちい）さい。 ・Translation: This screw is small in size. ・Explanation: This describes the size of the screw.

The etymology of ねじ ねじ is not definitively known, but it is believed to be derived from the verb 捻（ね）じる, which means "to twist" or "to screw." This reflects the primary function of a screw, which is to fasten objects by twisting.