The Collaborative International Dictionary of English v.0.48:

Testament \Tes"ta*ment\, n. [F., fr. L. testamentum, fr. testari
   to be a witness, to make one's last will, akin to testis a
   witness. Cf. Intestate, Testify.]
   1. (Law) A solemn, authentic instrument in writing, by which
      a person declares his will as to disposal of his estate
      and effects after his death.
      [1913 Webster]

   Note: This is otherwise called a will, and sometimes a last
         will and testament. A testament, to be valid, must be
         made by a person of sound mind; and it must be executed
         and published in due form of law. A man, in certain
         cases, may make a valid will by word of mouth only. See
         Nuncupative will, under Nuncupative.
         [1913 Webster]

   2. One of the two distinct revelations of God's purposes
      toward man; a covenant; also, one of the two general
      divisions of the canonical books of the sacred Scriptures,
      in which the covenants are respectively revealed; as, the
      Old Testament; the New Testament; -- often limited, in
      colloquial language, to the latter.
      [1913 Webster]

            He is the mediator of the new testament . . . for
            the redemption of the transgressions that were under
            the first testament.                  --Heb. ix. 15.
      [1913 Webster]

   Holographic testament, a testament written wholly by the
      testator himself. --Bouvier.
      [1913 Webster]

WordNet (r) 3.0 (2006):

testament
    n 1: a profession of belief; "he stated his political testament"
    2: a legal document declaring a person's wishes regarding the
       disposal of their property when they die [syn: will,
       testament]
    3: strong evidence for something; "his easy victory was a
       testament to his skill"
    4: either of the two main parts of the Christian Bible

Easton's 1897 Bible Dictionary:

Testament
   occurs twelve times in the New Testament (Heb. 9:15, etc.) as
   the rendering of the Gr. diatheke, which is twenty times
   rendered "covenant" in the Authorized Version, and always so in
   the Revised Version. The Vulgate translates incorrectly by
   testamentum, whence the names "Old" and "New Testament," by
   which we now designate the two sections into which the Bible is
   divided. (See BIBLE.)


Bouvier's Law Dictionary, Revised 6th Ed (1856):

TESTAMENT, civil law. The appointment of an executor or testamentary heir,
according to the formalities prescribed by law. Domat, Liv. 1, tit. 1, s. 1.
     2. At first there were only two sorts of testaments among the Romans
that called calatis comitiis, and another called in procinctu. (See below.)
In the course of time these two sorts of testament having become obsolete, a
third form was introduced, called per aes et libram, which was a fictitious
sale of the inheritance to the heir apparent. The inconveniences which were
experienced from these fictitious sales again changed the form of
testaments; and the praetor introduced another which required the seal of
seven witnesses. The emperors having increased the solemnity of those
testaments, they were called written or solemn testaments, to distinguish
them from nuncupative testaments which could be made without writing.
Afterwards military testaments were introduced, in favor of soldiers
actually engaged in military service.
     3. Among the civilians there are various kinds of testaments, the
principal of which are mentioned below.
     4. A civil testament is one made according to all the forms prescribed
by law, in contradistinction to a military testament, in making which some
of the forms may be dispensed with. Civil testaments are more ancient than
military ones; the former were in use during the time of Romulus, the latter
were introduced during the time of Coriolanus. See Hist. de la Jurisp. Rom.
de M. Terrason, p. 119.
     5. A common testament is one which is made jointly by several persons.
Such testaments are forbidden in Louisiana, Civ. Code of Lo. art. 1565, and
by the laws of France, Code Civ. 968, in the same words, namely, "A
testament cannot be made by the same act, by two or more persons, either for
the benefit of a third person, or under the title of a reciprocal or mutual
disposition."
     6. A testament calatis comitiis, or made in the comitia, that is, the
assembly of the Roman people, was an ancient manner of making wills used in
times of peace among the Romans. The comitia met twice a year for this
purpose. Those who wished to make such testaments caused to be convoked the
assembly of the people by these words, calatis comitiis. None could make
such will's that were not entitled to be at the assemblies of the people.
This form of testament was repealed by the law of the Twelve Tables.
     7. Testament ab irato, a term used in the civil law. A testament ab
irato, is one made in a gust of passion or hatred against the presumptive
heir rather than from a desire to benefit the devisee. When the facts of
unreasonable anger are proved, the will is annulled as unjust, and as not
having been freely made. Vide Ab irato.
     8. A mystic testament is also called a solemn testament, because it
requires more formality than a nuncupative testament; it is a form of making
a will, which consists principally in enclosing it in an envelope and
sealing it in the presence of witnesses.
     9. This kind of testament is used in Louisiana. The following are the
provisions of the civil code of that state on the subject, namely: the
mystic or secret testament, otherwise called the close testament, is made in
the following manner: the testator must, sign his dispositions, whether he
has written. them himself, or has caused them to be written by another
person. The paper containing, those dispositions, or the paper serving as
their envelope, must be closed and sealed. The testator shall present it
thus closed and sealed to the notary and to witnesses, or he shall cause it
to be and sealed in their presence; then he shall declare to the notary, in
the presence of the witnesses, that that paper contains his testament
written by himself, or by another by his direction, and signed by him, the
testator. The notary shall then draw up the act of superscription, which
shall be written on that paper, or on the sheet that serves as its envelope,
and that act shall be signed by the testator, and by the notary and the
witnesses. Art. 1577, 5 M. R. 1 82. All that is above prescribed shall be
done without interruption or turning aside to other acts; and in case the
testator, by reason of any hindrance that has happened since the signing of
the testament, cannot sign the act of superscription, mention shall be made
of the declaration made by him thereof; without its being necessary, in that
case, to increase the number of witnesses. Art. 1578. Those who know not
how, or are not able to write, and those who know not how, or are not able
to sign their names, cannot make dispositions in the form of the mystic
will. Art. 1579. If any one of the witnesses to the act of superscription
knows not how to sign, express mention shall be made thereof. In all cases
the act must be signed by at least two witnesses. Art. 1580.
     10. Nuncupative, testament, a term used in the civil law. A nuncupative
testament was one made verbally, in the presence of seven witnesses; it was
not necessary that it should have been, in writing; the proof of it was by
parol evidence.
     11. In Louisiana, testaments, whether nuncupative or mystic, must be
drawn up in writing, either by the testator himself, or by some other person
under his dictation. Civil Code of Lo. art. 1568. The custom of making
verbal statements, that is to say, resulting from the mere deposition of
witnesses, who were present when the testator made known to them his will,
without his having committed it, or caused it to be committed to writing, is
abrogated. Id. art. 1569. Nuncupative testaments may be made by public act,
or by act under private signature. Id. art. 1570. See Will, nuncupative.
     12. Olographic testament, a term used in the civil law. The olographic
testament is that which is written wholly by the testator himself. In order
to be valid, it must be entirely written, dated, and signed by the hand of
the testator. It is subject to no other form. See Civil Code of Lo. art.