A physical base or foundation.
A starting point, base or foundation for an argument or hypothesis.
An underlying condition or circumstance.
A regular frequency.
In a vector space, a linearly independent set of vectors spanning the whole vector space.
Amount paid for an investment, including commissions and other expenses.
A collection of subsets ("basis elements") of a set, such that this collection covers the set, and for any two basis elements which both contain an element of the set, there is a third basis element contained in the intersection of the first two, which also contains that element.