The word base has been around virtually unchanged since Ancient Greece as the word basis to denote a step or pedestal. Use of the word base as a chemical term to describe the chemical reactions of acids with other materials dates from 1754 and the French chemist Guillaume-Francois Rouelle. As the science of chemistry grew, the word base was refined to mean a susbstance that can accept hydrogen ions (protons) or donate electrons. Today there are several different definitions of the word, all corresponding to accepting protons or donating electrons.
Lithium Hydroxide (pictured above) is a typical strong base with a wide variety of uses: for respirator systems in spacecraft, as a battery electrolyte, in ceramics and some cements.
This memo is to remind all SHIELD employees that when we defeat an enemy and seize their installations and equipment, no one is to vocalize in any way whatsoever the phrase “all your base are belong to us.”