Luck into is a phrasal verb that means to gain or acquire something by chance or serendipity. There are several synonyms for the word "luck into" that can be used in different scenarios. Some of these synonyms include "stumble upon," "chance upon," "come across," "discover," and "unearth." These synonyms are commonly used in situations where someone finds or obtains something unexpectedly. For example, you might stumble upon a hidden treasure while hiking in the woods or chance upon a rare book at a garage sale. Regardless of the specific synonym used, they all convey the idea of gaining something valuable by chance or unexpected circumstances.