Definition of link up

• be or become joined or united or linked; "The two streets connect to become a highway"; "Our paths joined"; "The travelers linked up again at the airport"
• connect, fasten, or put together two or more pieces; "Can you connect the two loudspeakers?"; "Tie the ropes together"; "Link arms"
• make a logical or causal connection; "I cannot connect these two pieces of evidence in my mind"; "colligate these facts"; "I cannot relate these events at all"