base1
noun
1 the base of the tower:
foundation, bottom, foot, support, prop, stay, stand, pedestal, plinth, rest, bed, substructure.
▷antonyms top.
2 early learning will provide a sound base for what follows:
basis, bedrock, foundation, core, essence, essential, nitty-gritty, basics, starting point, key component, fundamental, root(s), heart, backbone, theory, principle, rationale;
source, origin, spring, well head, fountainhead, fount.
base (1) Oxford Dictionary of English