There are no dumb questions. ;)
Yes thats what it means, if you ground the enable pin that turns off the upconverter which turns off the +5V. And no drain on the battery.
I do it on my Powerboost 1000c’s. It lets me charge the battery but have the Boost section turned off. I have a toggle switch wired between the enable pin and a ground pin. An on off switch if you will.
A lot of the time the term “pin” will be used to denote a contact. The round hole where you would solder in a header (pin) for example. I do it all the time and don’t give it much thought. I probably should say contact though.