to make youthful; to restore youth to (someone or something)
intransitive verb
2.
to become youthful
Word origin
[1880–85; youth + -en1]This word is first recorded in the period 1880–85. Other words that entered Englishat around the same time include: barnstorm, interface, irredentist, quotation mark, rain check-en is a suffix formerly used to form transitive and intransitive verbs from adjectives(fasten; harden; sweeten), or from nouns (heighten; lengthen; strengthen)