The word "heapy" can be a bit tricky to find synonyms for, as it is a somewhat uncommon word. However, there are a few options that might work depending on the context. For example, "heapy" could be replaced with "piled," "stacked," or "accumulated" if referring to a large amount of something. Alternatively, if using "heapy" to describe something that is overflowing or excessively full, synonyms like "brimming," "spilling over," or "bursting" could be used. It's important to note that the best synonym will depend on the exact meaning and usage of "heapy" in your sentence or phrase.