Matching Pairs IDIOMS. AGEOnline version IDIOMS. AGE by María Marteles 1 silver surfer 2 rob the cradle 3 (live to a) ripe old age 4 to act your age 5 long in the tooth 6 mutton dressed as a lamb 7 to be knee-high to a grasshopper 8 feel your age 9 (be) over the hill 10 get on in years Someone who is growing old. Very young or small child Realize that you are no longer young An elderly person who uses the internet To live until you are very old. no to behave as someone younger Reach an age when you can no longer perform as well as before. a person who tries to look younger by wearing clothes designed for younger people Have a romantic relationship with someone who is much younger than yourself. Too old to do something