Launch into Definition 1 of 3Pro Tip 1/3Immediate Start Used when someone begins something abruptly, without hesitation or preparation. She launched into the presentation as soon as she entered the room. Pro Tip 2/3With Enthusiasm Implies intense eagerness or excitement about what is being started. He launched into explaining his idea with infectious enthusiasm. Pro Tip 3/3Subject Shift Indicates a sudden change to a new topic in conversation. Mid-conversation, she launched into a story about her dog.