There may be someplace in the world named Younkers (Yonkers, New York, is just one letter away!), but the word younker
refers to a person within a particular age group.
A younker is a young person, usually designating a male. At one time, mention of a younker meant reference to a gentleman or youthful noble.
Younkers pop up in literature, such as in Vanity Fair:
Then he said, "It's not respectful, sir, of you younkers to be imitating of your relations."
And, in Treasure Island:
"Jim," says he, "I reckon we're fouled, you and me, and we'll have to sign articles. I'd have had you but for that there lurch, but I don't have no luck, not I; and I reckon I'll have to strike, which comes hard, you see, for a master mariner to a ship's younker like you, Jim."
Oliver Twist qualifies as a younker in Charles Dickens' classic book:
". . . Sit down by the fire, younker, and rest yourself; for you'll have to go out with us again to-night, though not very far off."