* Verb (past participle): This is the most common use, meaning to press something flat. For example, "The bug was squashed under my foot."
* Adjective: This describes something that has been flattened or crushed. For example, "The squashed tomato was inedible."
* Noun: This is less common, but it can be used to refer to something that has been squashed. For example, "The squashed bug was a sight to behold."
So, the part of speech depends on the context in which the word is used!