definition of
link up

[1] #1 link up v. 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". wn

[2] #2 link up v. connect, fasten, or put together two or more pieces; "Can you connect the two loudspeakers?"; "Tie the ropes together"; "Link arms". wn

[3] #3 link up v. 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". wn