All depends on where you think one age ends and another begins. I use 18 to 35 for young adult and 36 to 65 for adult since most people I know in their 60s are not EA's definition of elder. Not even sure anyone under 70 fits that definition. For me, Adulthood is longer than young adulthood.
cheeky (comparative cheekier, superlative cheekiest) (informal) Impudent; impertinent; impertinently bold, often in a way that is regarded as endearing or amusing. 1899, Rudyard Kipling, chapter 4, in Stalky & Co.: Shut up, said Harrison. You chaps always behave as if you were jawin' us when we come to jaw you..
Synonyms: polished; dainty; twee; elegant; civilized; genteel; couth; cultivated; prim; suave; cultured; overrefined; well-bred; niminy-piminy; debonaire; superfine; ladylike; finespun; mincing; patrician; gentlemanlike; fastidious; polite; debonair; delicate; well-mannered; gracious; civilised; debonnaire; gentlemanly; Antonyms: ungracious; noncivilized