loutish adj.

1540s, "awkward fellow, boor, bumpkin," of uncertain origin. Perhaps a noun from a dialectal survival of Middle English louten (v.) "bow down" (c. 1300), from Old English lutan "bow low," from Proto-Germanic *lut- "to bow, bend, stoop" (source also of Old Norse lutr "stooping," which itself might also be the source of the modern English word).

According to Watkins this is from PIE *leud- "to lurk" (source also of Gothic luton "to deceive," Old English lot "deceit), also "to be small" (see little). Non-Germanic cognates probably include Lithuanian liūdėti "to mourn;" Old Church Slavonic luditi "to deceive," ludu "foolish." Sense of "cad" is first attested 1857 in British schoolboy slang.

adjectival word-forming element, Old English -isc "of the nativity or country of," in later use "of the nature or character of," from Proto-Germanic suffix *-iska- (cognates: Old Saxon -isk, Old Frisian -sk, Old Norse -iskr, Swedish and Danish -sk, Dutch -sch, Old High German -isc, German -isch, Gothic -isks), cognate with Greek diminutive suffix -iskos. In its oldest forms with altered stem vowel (French, Welsh). The Germanic suffix was borrowed into Italian and Spanish (-esco) and French (-esque). Colloquially attached to hours to denote approximation, 1916.

The -ish in verbs (abolish, establish, finish, punish, etc.) is a mere terminal relic from the Old French present participle.