launchday
nounUK /ˈlɔːntʃ deɪ/
US /ˈlɔːntʃ deɪ/
The day when something new starts or is sent off.
Everyone cheered on launch day when the rocket flew into the sky.
OTHER MEANINGS
2. The day a new product becomes available to buy.
The game store was crowded on launch day.
3. The day a ship or boat first goes into the water.
The whole town came to the harbor for the ship's launch day.
4. The day a website or app first opens to users.
The team worked late the night before launch day.