spring chicken vs younker

spring chicken and younker both are nouns.

Word	Noun	Adjective	Verb	Adverb
spring chicken	Yes	No	No	No
younker	Yes	No	No	No

As nouns, spring chicken and younker are synonyms defined as:

spring chicken and younker: a young person (especially a young man or boy)

Other synonyms of spring chicken include young person, youth.

spring chicken (noun)	younker (noun)
a young chicken having tender meat	a young person (especially a young man or boy)
a young person (especially a young man or boy)