Expresses rejuvenation or improvement in one's life or habits. After his retirement, grandpa started painting and truly seems to be getting younger.
Pro Tip 2/3
Complimenting Appearance
Often used as a compliment, implying someone looks younger than their age. Everyone says my mom is getting younger, especially since she got that new haircut.
Pro Tip 3/3
Subtle Changes
May refer to small changes that contribute to a youthful impression over time. With her new wardrobe, she's really getting younger every day.