Source : Webster's Revised Unabridged Dictionary (1913)

Base \Base\ (b[=a]s), a. [OE. bass, F. bas, low, fr. LL. bassus
   thick, fat, short, humble; cf. L. Bassus, a proper name, and
   W. bas shallow. Cf. {Bass} a part in music.]
   1. Of little, or less than the usual, height; of low growth;
      as, base shrubs. [Archaic] --Shak.

   2. Low in place or position. [Obs.] --Shak.

   3. Of humble birth; or low degree; lowly; mean. [Archaic] ``A
      pleasant and base swain.'' --Bacon.

   4. Illegitimate by birth; bastard. [Archaic]

            Why bastard? wherefore base?          --Shak.

   5. Of little comparative value, as metal inferior to gold and
      silver, the precious metals.

   6. Alloyed with inferior metal; debased; as, base coin; base
      bullion.

   7. Morally low. Hence: Low-minded; unworthy; without dignity
      of sentiment; ignoble; mean; illiberal; menial; as, a base
      fellow; base motives; base occupations. ``A cruel act of a
      base and a cowardish mind.'' --Robynson (More's Utopia).
      ``Base ingratitude.'' --Milton.

   8. Not classical or correct. ``Base Latin.'' --Fuller.

   9. Deep or grave in sound; as, the base tone of a violin. [In
      this sense, commonly written {bass.}]

   10. (Law) Not held by honorable service; as, a base estate,
       one held by services not honorable; held by villenage.
       Such a tenure is called base, or low, and the tenant, a
       base tenant.

   {Base fee}, formerly, an estate held at the will of the lord;
      now, a qualified fee. See note under {Fee}, n., 4.

   {Base metal}. See under {Metal}.

   Syn: Dishonorable; worthless; ignoble; low-minded; infamous;
        sordid; degraded.

   Usage: {Base}, {Vile}, {Mean}. These words, as expressing
          moral qualities, are here arranged in the order of
          their strength, the strongest being placed first. Base
          marks a high degree of moral turpitude; vile and mean
          denote, in different degrees, the want of what is
          valuable or worthy of esteem. What is base excites our
          abhorrence; what is vile provokes our disgust or
          indignation; what is mean awakens contempt. Base is
          opposed to high-minded; vile, to noble; mean, to
          liberal or generous. Ingratitude is base; sycophancy
          is vile; undue compliances are mean.