From Longman Dictionary of Contemporary Englisheverything/anything etc under the suneverything/anything etc under the sunALL/EVERYTHINGused to emphasize that you are talking about a large range of things You can buy jeans in every colour under the sun. → sun
Examples from the Corpus
everything/anything etc under the sun• Andrew and I spent many hours on the Windrush porch discussing almost everything under the sun from party politics to mystic transcendentalism.• They discussed everything under the sun.• Some people think that the police can do everything under the sun like, but of course you can't.• There literally is everything under the sun, and you're free to do as much or as little as you want. 