This is the 3235th most frequent Chinese word.
出發
To set off; to depart.
Here, '出發' is used to indicate the action of departing or starting a journey.
我們明早六點出發去機場。
We will leave for the airport at 6 AM tomorrow.
'出發' in this sentence describes the organized departure of the tour group toward their next destination.
旅行團準時從飯店出發前往景點。
The tour group departed from the hotel on time to go to the attraction.
In this usage, '出發' implies the act of setting out to ensure punctuality.