あくどい

First cited to 1694.^[1]

Ultimate derivation is unclear.

• One reference derives this from prefix あ (a, of uncertain meaning) + 諄い (kudoi, “repetitive, tedious, clunky, long-winded, insistent”).^[2]

  However, there is no apparent fitting prefix, only 亜 (a-, “sub-, -ous, -ite”, most often found in chemistry or biology).

• Described in another source as deriving from 灰汁 (aku, “lye; harshness ”) + suffixing element どい (doi).^[3] This doi is probably from now-archaic adjective 利し・鋭し・疾し・敏し (toshi), modernized form とい (toi, “sharp, biting; fierce, vicious; fast, quick”).

Considering the senses, this might be a case of separately derived homophones, or a case where separate partially-similar terms influenced the meaning.

• (Tokyo) あくどい (Nakadaka – )^[3][2][4]
• IPA^(key):

あくどい • (akudoi) -i (adverbial あくどく (akudoku))

1. harsh of manner or personality; vicious, wily, unscrupulous, villainous

   Synonym: (dishonest, unscrupulous) 悪徳 (akutoku)

   あくどい手(しゅ)段(だん)を使(つか)う。

   Akudoi shudan o tsukau.

   They use dirty tricks.

2. persistent or stubborn of manner; cloying of flavor; garish or overdone of color or appearance

   Synonyms: (persistent of manner or flavor) しつこい (shitsukoi), (overdone, garish) どぎつい (dogitsui)