(covers information from several alternate timelines)
A christening was a ceremony in which a ship was officially given its name and launched.
In 2258 of the alternate reality, Captain Christopher Pike expressed his regret that the maiden voyage of the USS Enterprise wasn't grander, saying that the ship's christening would be their reward for a safe return. (Star Trek)
In 2259, James T. Kirk spoke at the re-christening of the Enterprise following Khan Noonien Singh's attack on San Francisco. (Star Trek Into Darkness)
In 2293, the USS Enterprise-B was christened with a bottle of Dom Pérignon, vintage 2265. (Star Trek Generations)
In 2376, Tom Paris asked Neelix for a bottle of champagne so he could christen Alice. The cook offered to make hors d'œuvres for the crew, but Paris declined, saying he and B'Elanna Torres were going to attend alone. (VOY: "Alice")
In the 2380s, the USS Protostar was christened with a bottle of Chateau Picard wine. (PRO: "Asylum")