Frances to Armando with thanks... The word "grounded" here as given by you is not fully clear to me, but if by "grounded" you mean placed or built on the land or on and in the water or in the air, then this might also presumably include say docking stations under the sea or in outer space. Furthermore, if the once "entrance" were later sealed by design as in say a tomb, would the "thing" remain as architecture in the absence of an entrance, or perhaps would it now become as sculpture. You may have also unwittingly indicated a problem in the English language when it comes to the term "architecture" when commonly used only as a general class or field of activity and study. My preference is to sometimes use it aligned with graphic pictures and plastic sculptures and so tectonic architectures, and thus a singular edifice would be called an architecture. This lingual usage of the word however is not always accepted. Allow me to search further into the origins and sources of the word.
You wrote... Architecture are grounded things with an entrance.
