Before World War 1, Poland was partitionned between Prussia, Austria-Hungary and Russia. However I have strong reasons to suspect that the word "Poland" was at that time referring specifically to the Russian partition.
Example in this map, the word "Poland" is clearly written over the Russian partition, and it is very clear it is not referring to any part of Germany nor Austria-Hungary. I saw other maps where it was the same.
Also, last but not least, people asking polish-related questions on Genealogy stack exchange typically ask questions referring Russia's Poland as simply "Poland", while those referring to Austrian-Hungarian or German "Poland" will refer it as "Austria-Hungary" or "Germany" respectively.