This is the 12174th most frequent Polish word.
martwi
"Martwi" means "worries" or "is concerned" in English.
In this case, 'martwi' is a verb in the third-person singular form, meaning 'worries.' It signifies causing concern to someone.
Ten temat martwi nas wszystkich.
This topic worries us all.
In this sentence, 'martwi' is used as a verb in the reflexive form 'martwi się,' meaning 'worries.' It expresses concern or anxiety about something or someone.
On martwi się o swoje dzieci.
He worries about his children.
Here, 'martwi' functions as a noun (plural form), meaning 'the dead.' It refers to those who have passed away.