This is the 258th most frequent Lithuanian word.
meras
"Mer as" means "mayor" in English.
Here, 'meras' is used as a noun meaning 'mayor', which is the head of a city council.
Mūsų miesto meras yra labai atsakingas žmogus.
The mayor of our city is a very responsible person.
In this sentence, 'meras' is used as a noun again, describing a position or a role in office.
Kaip meras, jis priima sprendimus, kurie veikia visą miestą.
As a mayor, he makes decisions that affect the entire city.
Here, 'mero' is the possessive form of 'meras', showing possession (the mayor's proposal).