Definition
To do something 'terrestrially' means to do it in a way that relates to the Earth or land. It implies a focus on earthly matters, as opposed to those of outer space or the sea. This can involve studying landforms, living organisms on land, or the physical properties of the Earth. Think of it as anything that's 'down to earth'. It suggests a grounded perspective, focused on the world around us. It's the opposite of things that are 'celestial'.