市民 means "citizen" or "town/city resident" and refers to the people who live in a particular city or municipality. It combines 市 (city) with 民 (people). It is commonly used in news and formal contexts, as in 当地市民 (local residents).
市民们对新建的公园非常满意。
shìmínmen duì xīn jiàn de gōngyuán fēicháng mǎnyì.
The citizens are very satisfied with the newly built park.
当地市民纷纷参加了志愿活动。
dāngdì shìmín fēnfēn cānjiāle zhìyuàn huódòng.
Local citizens participated in volunteer activities one after another.
政府正在听取市民的意见。
zhèngfǔ zhèngzài tīngqǔ shìmín de yìjiàn.
The government is listening to the opinions of the citizens.