caddish adj.

1730, shortening of cadet (q.v.); originally used of servants, then (1831) of town boys by students at Oxford and English public schools (though at Cambridge it meant "snob"), then "townsman" generally. Compare caddie. The meaning "person lacking in finer feelings" is from 1838.

A cad used to be a jumped-up member of the lower classes who was guilty of behaving as if he didn't know that his lowly origin made him unfit for having sexual relationships with well-bred women. [Anthony West, "H.G. Wells: Aspects of a Life," 1984]

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.