The Collaborative International Dictionary of English v.0.48:
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
peasant 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
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 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;
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 lack 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.
Bouvier's Law Dictionary, Revised 6th Ed (1856):
BASE FEE, English law. A tenure in fee at the will of the lord. This was
distinguished from socage free tenure. See Co. Litt. 1, 18.