base

base

noun \ˈbās\

plural bas·es \ˈbā-səz\

Definition of BASE

1

: that portion of a bodily organ or part by which it is attached to another more central structure of the organism <the base of the thumb>

2

a : the usually inactive ingredient of a preparation serving as the vehicle for the active medicinal preparation <the fatty base of an ointment> b : the chief active ingredient of a preparation—called also basis

3

a : any of various typically water-soluble and bitter tasting compounds that in solution have a pH greater than 7, are capable of reacting with an acid to form a salt, and are molecules or ions able to take up a proton from an acid or are substances able to give up an unshared pair of electrons to an acid—compare alkali b : any of the five purine or pyrimidine bases of DNA and RNA that include cytosine, guanine, adenine, thymine, and uracil

4

: freebase

—based \ˈbāst\ adjective