This is the 13253rd most frequent Polish word.
opisem
"Opis" in Polish means "description," and "opisem" is its instrumental case, meaning "with a description" or "by description."
In this sentence, 'opisem' is used as the instrumental form of 'opis', which means 'description'. It describes the manner or tool by which the study was enriched.
Opracowanie było wzbogacone szczegółowym opisem.
The study was enriched with a detailed description.
Here, 'opisem' denotes the instrumental case showing the means or object of inspiration—the description.
Zainspirowałem się opisem w przewodniku.
I was inspired by the description in the guidebook.
In this context, 'opisem' serves again as the instrumental form, illustrating the object being engaged with—namely, the description of the activities.