Grown up
Another word starting with g is gloominess
global
ghoul
gnashing
grate, grill
Maybe Gratis is a word that would work.
Glitterati
ge he made me do it {make sure he is and adult}
A beverage starting with the letter "g" can be Gatorade... or if you found another answer, then great.
Another word for accepted fact starting with "g" is "given." In the context of research or problem-solving, a given is a known or established fact that is accepted without needing further proof. This term is commonly used in mathematics, science, and other analytical fields to establish a starting point for analysis or discussion.
Another 'g' word for gadget is gizmo or gismo.
Gazelle