This is the 4266th most frequent Polish word.
duchu
The Polish word "duchu" means "spirit" or "soul" (in the genitive or locative case).
Here, 'duchu' functions in the locative case of the noun 'duch', meaning 'spirit' or 'esprit', indicating the manner or quality (in the spirit of solidarity).
Zawsze pamiętaj o duchu solidarności.
Always remember the spirit of solidarity.
In this sentence, 'duchu' again is the locative case of 'duch', here referring to a spirit or ghost, often associated with folklore or legends.
W starym zamku można poczuć obecność duchu.
In the old castle, one can feel the presence of a spirit.
Here, 'duchu' remains in the locative case but is used metaphorically to describe an approach or attitude toward faith and hope.