Can I add “open in terminal” to the right-click mouse menu in Lubuntu?

Well, given that Lubuntu is thought of as a "lighter" distro, we'll find quite a few favorite features totally missing or not where we'd expect them to be. In this specific case, if you navigate to a particular folder in PCManFM, please press F4 to open a terminal in the current folder. (You can see the F4 option and others such as "Open Current Folder as Root" in the Menu, Tools dropdown of PCManFM.)

This doesn't mean that there isn't a way to add the "open terminal here" to PCManFM's right-click menu. But I don't know of one. Instead, I've installed Thunar, the file manager by default in Xubuntu, and that does have the option you want along with useful things like Custom actions.

Edit (2015-05-06): Technically, as of when this answer was originally answered, the answer is "No, you cannot add this functionality in any way". However, this may mean I simply do not know if there is a way.

Ah, I finally noticed how PCManFM does it while watching a video review of said OS.

To open a terminal in a folder, simply move "outside" the folder, right-click on said folder, and the option to open folder in terminal will be in the right-click menu.

For example, say I want to open a terminal in my "Downloads" folder:

1. Move "outside" or "above" the folder, which in this case would be my home folder, /home/lubuntuUsername
2. Right-click on the "Downloads" folder
3. Select "Open in Terminal"

After following these steps, a terminal should open, with the path set as lubuntuUsername@computerName:~/Downloads$

According to Add Open Folder as Root to PCMan File Manager's context menu , you can create terminal.desktop in ~/.local/share/file-manager/actions/

And add content like this

[Desktop Entry]
Type=Action
Tooltip=Open Terminal
Name=Open Terminal
Profiles=profile-one;
Icon=utilities-terminal


[X-Action-Profile profile-one]
MimeTypes=inode/directory;
Exec=deepin-terminal -w %f
Name=Default profile

I use Deepin Terminal so my Exec is deepin-terminal -w %f. You should change this if you use other terminal. For example, you can use gnome-terminal --working-directory %f for Gnome Terminal.