定規・定木|じょうぎjougi[1]atamadaka (head-high)

1. noun(measuring) ruler
   私は本ほんを買かい、彼かれは定規じょうぎを買かった。↗

   I bought a book and he a ruler.

• Synonym物差しものさしNeutralA ruler for measuring length, but also used figuratively for a standard of judgment, as in 「自分の物差し」; 「定規」 is mainly a ruler for drawing straight lines.
• SynonymメジャーNeutralA loanword mostly for a tape measure, as in 「メジャーで測る」; 「定規」 is a straight ruler for drawing lines.
• SynonymルーラーNeutralA loanword for a straight ruler, but rarely used in everyday speech; 「定規」 is the usual word.
• Related尺度しゃくどWrittenA written-style word: mostly an abstract standard or criterion, as in 「評価の尺度」; 「定規」 is chiefly the physical ruler, though it can also mean a standard or model.
• RelatedメジャーNeutralA loanword mostly for a tape measure, as in 「メジャーで測る」; 「定規」 is a straight ruler for drawing lines.
• Related罫引きけびきNeutralA woodworking tool for marking parallel lines on wood; 「定規」 is a general ruler for drawing lines and measuring length.

Use 「定規」 for a ruler to draw straight lines or measure length. For measuring you can also say 「物差し」, which doubles as a metaphor for a standard; use 「メジャー」 for a tape measure and 「尺度」 for an abstract standard.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 直線ちょくせんまたは曲線きょくせんなどの線せんを描えがくための用具ようぐ。
2. 標準ひょうじゅん。規則きそく。手本てほん。