The Collaborative International Dictionary of English v.0.48:

Voluntary \Vol"un*ta*ry\, a. [L. voluntarius, fr. voluntas will,
   choice, from the root of velle to will, p. pr. volens; akin
   to E. will: cf. F. volontaire, Of. also voluntaire. See
   Will, v. t., and cf. Benevolent, Volition,
   Volunteer.]
   1. Proceeding from the will; produced in or by an act of
      choice.
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            That sin or guilt pertains exclusively to voluntary
            action is the true principle of orthodoxy. --N. W.
                                                  Taylor.
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   2. Unconstrained by the interference of another; unimpelled
      by the influence of another; not prompted or persuaded by
      another; done of his or its own accord; spontaneous;
      acting of one's self, or of itself; free.
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            Our voluntary service he requires.    --Milton.
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            She fell to lust a voluntary prey.    --Pope.
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   3. Done by design or intention; intentional; purposed;
      intended; not accidental; as, if a man kills another by
      lopping a tree, it is not voluntary manslaughter.
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   4. (Physiol.) Of or pertaining to the will; subject to, or
      regulated by, the will; as, the voluntary motions of an
      animal, such as the movements of the leg or arm (in
      distinction from involuntary motions, such as the
      movements of the heart); the voluntary muscle fibers,
      which are the agents in voluntary motion.
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   5. Endowed with the power of willing; as, man is a voluntary
      agent.
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            God did not work as a necessary, but a voluntary,
            agent, intending beforehand, and decreeing with
            himself, that which did outwardly proceed from him.
                                                  --Hooker.
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   6. (Law) Free; without compulsion; according to the will,
      consent, or agreement, of a party; without consideration;
      gratuitous; without valuable consideration.
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   7. (Eccl.) Of or pertaining to voluntaryism; as, a voluntary
      church, in distinction from an established or state
      church.
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   Voluntary affidavit or Voluntary oath (Law), an affidavit
      or oath made in an extrajudicial matter.

   Voluntary conveyance (Law), a conveyance without valuable
      consideration.

   Voluntary escape (Law), the escape of a prisoner by the
      express consent of the sheriff.

   Voluntary jurisdiction. (Eng. Eccl. Law) See Contentious
      jurisdiction, under Contentious.

   Voluntary waste. (Law) See Waste, n., 4.
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   Syn: See Spontaneous.
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Bouvier's Law Dictionary, Revised 6th Ed (1856):

VOLUNTARY CONVEYANCE, contracts. The transfer of an estate made without any
adequate consideration of value.
     2. Whenever a voluntary conveyance is made, a presumption of fraud
properly arises upon the statute of 27th Eliz. cap. 4, which presumption may
be repelled by showing that the transaction on which the conveyance was
founded, virtually contained some conventional stipulations, some compromise
of interests or reciprocity of benefits, that point out an object and motive
beyond the indulgence of affection or claims of kindred, and not
reconcilable with the supposition of intent to deceive a purchaser. But
unless so repelled, such a conveyance coupled with a subsequent negotiation
for sale, is conclusive evidence of statutory fraud. 5 Day, 223, 341; 1
Johns. Cas. 161; 4 John. Ch. R. 450; 3 Conn. 450; 4 Conn. 1; 4 John. R. 536;
15 John. R. 14; 2 Munf. R. 363. A distinction has been made between previous
and subsequent creditors; such a conveyance is void as to the former but not
as to the latter. 8 Wheat. 229; 3 John. Ch. 481; and see 6 Alab. R. 506; 9
Alab. R. 937; 10 Conn. 69. And a conveyance by a father who, though in debt,
is not in embarrassed circumstances, who makes a reasonable provision for a
child, leaving property sufficient to pay his debts, is not per se,
fraudulent. 4 Wheat. 27; 6 Watts & S. 97; 4 Vern. 889; 6 N. H. Rep. 67; 11
Leigh, 137; 5 Ohio, 121.
     3. By the statute of 3 Henry VII. c. 4, all deeds of gifts of goods and
chattels in trust for the donor were declared void; and by the statute of 13
Eliz. ch. 5, gifts of goods and chattels, as well as of lands, by writing or
otherwise, made with intent to delay, hinder and defraud creditors, were
rendered void as against the person to whom such frauds would be
prejudicial.
     4. The principles of these statutes, which indeed have been copied from
the civil law, Dig. 42, 8, 5, 11; 2 Bell's Com. 182, though they may not
have been substantially reenacted, prevail throughout the United States. 8
Johns. Ch. R. 481; 1 Halst. R. 450; 5 Cowen, 87; 8 Wheat. R. 229; 11 Id.
199; 12 Serg. & Rawle, 448; 9 Mass. R. 390; 11 Id. 421; 4 Greenl. R. 52; 2
Pick. R. 411; 8 Com. Dig. App. h.t.; 22 Vin. Ab. 15; 1 Vern. 38, 101; Rob.
on Fr. Conv. 65, 478 Dane's Ab. Index, h.t.; 14 Ves. 344; 4 McCord, 294; 1
Rawle. 231; 1 Rep, Const. Ct. 180; 1 N. & McCord, 334; Coxe, 56; Hare &
Wall. Sel. Dee. 33-69. Vide Contracts; Indebtedness; Settlement.
     5. As between the parties such conveyances are, in general, good. 2
Rand. 384; 1 John. Chan. R. 329, 336; 1 Wash. 274 And when it has once been
executed and delivered, it cannot be recalled; even where an unmarried man
executes a voluntary trust deed for the benefit of future children, nor can
he relieve himself from a provision in the conveyance to the trustee, under
which the income of the trust property is to be paid to him at. the
discretion of a third person. 2 My. & Keen, 496. See 2 Moll. 257.