Run into: To unexpectedly meet or encounter someone or something. Example: While exploring the city, I ran into an old friend from school. Stumble upon: To find or discover something unexpectedly or by chance. Example: During my hike, I stumbled upon a hidden waterfall in the forest. Hang out: To spend time together casually in a relaxed manner. Example: We decided to hang out at the beach and enjoy the beautiful sunset. Come across: To encounter or find unexpectedly. Example: While cleaning the attic, I came across an old box of family photographs.