act your age!

This expression is used to tell someone to stop being silly or childish and behave in a more mature way.
“Come on boys! Stop being so silly and act your age!

age before beauty

‘Age before beauty’ is a teasing, playful (and slightly rude) way of indicating to someone that they should go first.
“As he held the door open Charlie said “Go ahead please. Age before beauty, you know!”

get on in years

Someone who is getting on in years is growing old.
“My grandmother is getting on in years. She’s no longer able to look after her home without help.”

knee-high to a grasshopper

This term refers to a very young and therefore small child.
“Last time I saw you, you were knee-high to a grasshopper!”

long in the tooth

A person who is long in the tooth is a bit too old to do something.
“She’s a bit long in the tooth for a cabaret dancer, isn’t she?”

mutton dressed as lamb

This expression refers to a middle-aged woman who tries to look younger by dressing in clothes designed for younger people.
“The style doesn’t suit her – it has a mutton-dressed-as-lamb effect on her”

no spring chicken

To say that someone is no spring chicken means that they are quite old or well past their youth.
“How old is the owner? I don’t know but she’s no spring chicken!”

(be) over the hill

If a person is over the hill, they have reached an age when they can no longer perform as well as before.
“Gran! You say you’re over the hill, but you’re a super cook!”

(live to a) ripe old age

This expression means to live until you are very old.
“If you lead a healthy life you’ll live to a ripe old age.” said the doctor.”

rob the cradle

If you rob the cradle, you have a romantic relationship with someone who is much younger than yourself.
“My uncle Ted is dating a twenty-year-old girl. That’s really robbing the cradle!”

senior moment

A momentary lapse of memory, especially in older people, or an absent-minded action such as putting the cereals in the refrigerator,
is humorously referred to as having a senior moment.
“I found the phone in the cupboard. I must have had a senior moment!”

silver surfer

A silver surfer is an elderly person who uses the internet.
“After just a few questions my grandmother was ready to join the silver surfers.”

put years on someone

If an event or difficult situation puts years on someone, it makes them look or feel much older.
“I hardly recognized Mr. Brown. His illness has put years on him.”