As you explained, Inception is an event that is a beginning; a first part or stage of subsequent events.

In this movie, lead protagonist **Dominic Cobb(Leonardo DiCaprio)** has got a task to implant an idea into Robert Fischer's subconscious mind by going into his dream. And that person will have a life and act according to what has been implanted into his mind.

Therefore, in this case, **inception is just an activity to plant an idea into someone else's brain to start a chain of events.**