1 young /ˈjʌŋ/ adjective
younger /ˈjʌŋgɚ/ ; young /-gəst/ /ˈjʌŋgəst/
1 young
younger /ˈjʌŋgɚ/ ; young /-gəst/ /ˈjʌŋgəst/
Learner's definition of YOUNG
: in an early stage of life, growth, or development : not yet old
: recently formed, produced, started, etc.

not getting any younger

informal + humorous
used to say that someone is getting older and may not have much more time to do something

the younger

used in comparing the ages of two people who are members of the same family
used to refer to the younger of two people (such as a father and son) who have the same name

years young

used to describe an older person's age in a way that is meant to suggest that the person still looks or feels young

you're only young once

used to say that people should enjoy themselves while they are young
2 young /ˈjʌŋ/ noun
2 young
Learner's definition of YOUNG
the young : young people
[plural] : young animals, birds, etc.

young and old

: young and old people