polish people told me that I should use pieczarka instead of grzyb. Are they synonyms? Maybe it's a stupid question but it occurred to me that I learned the wrong translation for some words so I want to be sure
Pieczarka is one of types of „grzyb” (mushrooms). If you were to think about a mushroom it would probably be „pieczarka”.
Pieczarka (plural Pieczarki)
Other kinds of grzyb (examples):
Kurka (also: Pieprznik jadalny)
Those are some fantastic mushrooms pictures. Thanks for the insight.
No, your original guess was right. Mucho + mór -- "fly" + (old-fashioned word for) "kill".
The thing is, that most of English-speaking people seem not to have much knowledge about mushrooms. But in Poland, they are a lot more often used in our dishes. And 'pieczarka' is the most widely known, even in countries that are not very fond of mushrooms. I would even think of it as something separate, although it technically is a mushroom as well, of course.