English Idioms and Idiomatic Expressions 

Idioms relating to Age
 from: 'act your age'   to:  'put years on someone'

• 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."