This is the 164th most frequent Polish word.
mężczyzna
"Man" or "male person."
The word 'mężczyzna' is used as a subject of the sentence, referring to a person who is male, described with the adjective 'wysoki' meaning 'tall'.
Ten mężczyzna jest wysoki.
This man is tall.
In this sentence, 'mężczyzna' appears in the dative case (mężczyźnie), following the verb to indicate the recipient of the action.
Dziecko podarowało coś mężczyźnie.
A child gave something to the man.
Here, 'mężczyzna' is in the instrumental case (mężczyzną), used after the preposition 'z' for indicating 'with a man'.