This is the 13835th most frequent Polish word.
pokrzywą
"Pokrzywą" means "under the nettle" in English.
The word 'pokrzywa' is used as a noun in singular nominative form, referring to the plant.
W ogrodzie rośnie pokrzywa.
There is a nettle growing in the garden.
Here, 'pokrzywy' is in singular genitive case, showing that the action 'dotknąć' refers to it.
Dotknąłem się pokrzywy i poparzyłem rękę.
I touched a nettle and burned my hand.
In this context, 'pokrzywy' is in singular genitive case, indicating that the tea is made from it.