https://marcinciura.wordpress.com/2018/07/14/polish-word-rectangles/

In typical Polish crosswords, only nouns in their base form are allowed. These are the only four 7 × 7 squares whose rows and columns are Polish common nouns:
C E R A M I K
E F E M E R A
R E K E T E R
A M E J/B O Z A
M E T O D Y K
I R E Z Y N A
K A R A K A L/N

Używa innego słownika niż ja, rzeczniki tylko, i dość brzydkie. Brzmi jak czelendż. dx