Shift + Insert usually works throughout X11.
On windows 7:
Ctrl + Shift + Ins
works for me!
same for Terminator
Ctrl + Shift + V
Look at your terminal key-bindings if any if that doesn't work
Mostly likely middle click your mouse.
Or try Shift + Insert.
It all depends on terminal used and X11-config for mouse.
In Konsole (KDE terminal) is the same, Ctrl + Shift + V
Source: Stackoverflow.com