dis-(off, away) + cernere(distinguish, separate, sift)

discrete(別々の)と語源が一緒で発音も同じ

分離→分別

思慮分別のある慎重さ

source: [しーっ｜無料GIF画像検索 GIFMAGAZINE 3005666]

adjective (discreeter, discreetest)

careful and circumspect in one's speech or actions, especially in order to avoid causing offense or to gain an advantage: 人のスピーチや行動が注意深く慎重な. 特に気を悪くするのを防いだり、優位に立つ目的で

〈人･行動･態度などが〉思慮深い; «…について/…(すること)に» 慎重な, 口がかたい «about/in (doing)» (↔ indiscreet)

e.g. we made some discreet inquiries.: 私達は思慮深い質問をした

intentionally unobtrusive: 故意に目立たないように

｟ほめて｠ 〈装飾品･色などが〉控えめな, 目立たない

e.g. a discreet cough.: 目立たないような咳

discreetness | dəˈskrētnəs | noun

Middle English: from Old French discret, from Latin discretus ‘separate’, past participle of discernere ‘discern’, the sense arising from late Latin discretio (see discretion). Compare with discrete.

The words discrete and discreet are pronounced in the same way and share the same origin but they do not mean the same thing. Discrete means ‘separate,’ as in a finite number of discrete categories, while discreet means ‘careful and circumspect,’ as in you can rely on him to be discreet.