A mi sheberach is the prayer said in shul, blessing a particular person or group. The name comes from the opening of the prayer, which means May the One who blesses. The first mi sheberach appears in the Machzor Vitri (13th century). This is the prayer that we still say for the wellbeing of the community, especially its leaders and machers. In Ashkenazi communities the custom emerged of saying individualised mi sheberachs for those called up to the Torah. This practice also continues. In many communities, it has been developed to include mi sheberach for the wife and children of the oleh (the person called to the Torah) and extended family, too. Receiving a mi sheberach is understood to confer an obligation to give charity. Some shuls have a special mi sheberach for those who dont talk during services. People think this is a new-fangled custom to promote decorum in our irreverent age. In fact it dates back to Rabbi Yomtov Lipmann Heller, a student of the Maharal of Prague in the 17th century. Some things dont change. Jonathan Gillis of Sunderland and Jerusalem pointed out to me of the ironic use of the phrase mi sheberach, meaning to give somebody an earful or curse them out. In this sense, you could say, for example, I got home after midnight; oy, what a mi sheberach she gave me.