This is the 88th most frequent Marathi word.
मर
"मर" in English means "die" or "perish."
Here, 'मर' is used in the sense of being deeply fond of or loving something.
तू त्या चित्रावर मरत आहेस.
You are very much fond of that picture.
In this sentence, 'मर' is used literally to describe the natural death or withering of living things.
त्या झाडाचे पान काही दिवसांत सुकून मरतील.
The leaves of that tree will wither and die in a few days.
Here, 'मर' figuratively means to be overly eager or desperate for something.