verb/ʁa.ʒœ.niʁ/
to rejuvenate; to make young; to take off (years from someone's age) (to make appear younger); to bring back; to send back (remind of a past time); to get younger
“Ce costume le rajeunit de 10 ans.” — This costume takes 10 years off him.
From r- + a- + jeune + -ir.