1. To accompany someone out (of some place or event). In this usage, a noun or pronoun can be used between "usher" and "in." I don't know why they thought they needed to have security usher me out—I made it perfectly clear I would leave peacefully. Martin, please quickly and quietly usher out the guests, but try not to make a stir while you do.

2. To mark the end, departure, or replacement of some person or thing. The new government seems eager to usher out the policies of its predecessors. Though a great deal of incidents and influences contributed, it was Gorbachev's resignation as general secretary that truly ushered out the Soviet Union.