The transparency feature was indeed removed from the recent versions of the Gnome Terminal. As noted in the other answers, you could use Devil's Pie program to make any window transparent (and more).
Here's how to set this up in Devils Pie 2 (it uses Lua, so scripts for the original Devil's Pie are not compatible with this version). I'm using Debian Buster, but it should work the same in Ubuntu.
- Install Devil's Pie 2 right from the official repo:
sudo apt install devilspie2.
~/.config/devilspie2/gnome-terminal.lua with the following contents:
if (get_window_name()=="Terminal") then
~/.config/autostart/devilspie.desktop file, which something like this inside:
Comment="The Devil Spy 2 script"
- Logout and login again or just reboot. All set!
In the Lua script, you could tweak the
means that the window will be
You can also add any other command which Devil's Pie 2 supports. The list could be found here.