A colloquial expression meaning so many that one cannot use them all; 'countless' or 'rolling in (money)'.
あの店にはお菓子が腐るほど置いてある。
That shop has sweets in abundance (literally: so many they could rot).
お金が腐るほどあったら、世界一周旅行に行きたい。
If I had loads of money, I'd go on a trip around the world.
ネットには参考になる例文が腐るほどあるから、探してみて。
There are tons of useful example sentences on the internet, so try looking for them.
倉庫には古い家具が腐るほど積んであった。
The warehouse was piled with so much old furniture it seemed endless.