From Longman Dictionary of Contemporary Englishover the hillover the hillOLD/NOT NEWno longer young, and therefore no longer attractive or good at doing things Kathleen thinks she’s over the hill, but she’s only 32. → hill
Examples from the Corpus
over the hill• At 32, many considered Ali to be over the hill as a professional boxer.• At 32, many considered Ali to be over the hill.• In the morning it looks like a smoky haze is hanging over the hills.• Mývatn is over the hill, past more vile-smelling industrial delights.• He said vandals had cut through another part of the fence just over the hill.• Go tell it on the mountain, over the hills and everywhere.• So Flora put on her green wellies and Jane her black ones, and they marched out over the hills.• When wandering over the hills we met a shepherd, exchanged courtesies, and offered him a glass. 