usher in

begin, commence, start, initiate, inaugurate, usher in mean to take the first step in a course, process, or operation. begin, start, and commence are often interchangeable. begin, opposed to end, is the most general.

• • begin a trip
• • began dancing

start, opposed to stop, applies especially to first actions, steps, or stages.

• • the work started slowly

commence can be more formal or bookish than begin or start.

• • commence firing
• • commenced a conversation

initiate implies taking a first step in a process or series that is to continue.

• • initiated diplomatic contacts

inaugurate suggests a beginning of some formality or notion of significance.

• • the discovery of penicillin inaugurated a new era in medicine

usher in is somewhat less weighty than inaugurate.

• • ushered in a period of economic decline