As you may know, Xfce4 terminal supports the Quake style drop-down mode since version 0.6. Just a parameter --drop-down will start xfce4-terminal just like quake, yakuake, or tilda.

It is advised to bind this feature to a shortcut in the keyboard preferences. Below steps will teach you how:

1. Open xfce4-setting-manager from Application menu or Alt+F2 Application Finder box.

2. Click on the Keyboard icon under Hardware section.

3. Under Application Shortcuts tab, click on the Add button and type in the command box xfce4-terminal --drop-down

4. Click on OK and set a keyboard shortcut in next window.

Now you’re able to press the keyboard shortcut to launch a drop-down Xfce4 terminal. Click the button at right-bottom to open the preferences dialog and edit the width, height, opacity, duration and more!

Sumber: https://ubuntuhandbook.org/index.php/2014/02/launch-xfce4-terminal-in-quake-style-drop-down-mode/