Meaning

adjective used of the younger of two persons of the same name especially used to distinguish a son from his father

adjective (used of living things especially persons) in an early period of life or development or growth

adjective (of crops) harvested at an early stage of development; before complete maturity

origin* An English (mainly Northumberland and eastern Scotland) surname from Middle English yungre (“younger”), used to distinguish younger and older men with the same name. * In at least one case (of an immigrant Fleming), probably an Americanized form of Middle Dutch jongheer (“young nobleman”). * Americanized form of cognate or like-sounding names, notably German Junger, Junker and Dutch Jonker.

Etymology from Wiktionary, CC BY-SA 3.0