trover:

1. A common-law action for the recovery of damages for the conversion (i.e. “illegal selling or giving away of”) of personal property, the damages generally being measured by the property’s value. — aka trover and conversion. [1]

     Excerpt from Benjamin J. Shipman’s Handbook of Common-Law Pleading (Henry Winthrop Ballantine Ed., 3rd Ed. 1923):

     “Trover may be maintained for all kinds of personal property, including legal documents, but not where articles are severed from land by an adverse possessor, at least until recovery of possession of the land.  It lies for the misappropriation of specific money, but not for breach of an obligation to pay where there is no duty to return specific money.” [2]

conversion:
n. (14c.)

1. The act of changing from one form to another; the process of being exchanged.

2. Tort & criminal law.  The wrongful possession or disposition of another’s property as if it were one’s own; an act or series of acts of willful interference, without lawful justification, with an item of property in a manner inconsistent with another’s right, whereby that other person is deprived of the use and possession of the property. — convert, vb. — conversionary, adj. [1]

     Excerpt from R.F.V. Heuston’s Salmond on the Law of Torts (17th ed. 1977):

     “There are three distinct methods by which one man may deprive another of his property, and so be guilty of a conversion and liable in an action for trover —

(1) by wrongly taking it,
(2) by wrongly detaining it, and
(3) by wrongly disposing of it.

     The term conversion was originally limited to the third of these cases.  To convert goods meant to dispose of them, or make away with them, to deal with them, in such a way that neither owner nor wrongdoer had any further possession of them: for example, by consuming them, or by destroying them, or by selling them, or otherwise delivering them to some third person.  Merely to take another’s goods, however wrongfully, was not to convert them. Merely to detain them in defiance of the owner’s title was not to convert them. The fact that conversion in its modern sense includes instances of all three modes in which a man may be wrongfully deprived of his goods, & not of one mode only is the outcome of a process of historical development whereby, by means of legal fictions and other devices, the action of trover was enabled to extend its limits and appropriate the territories that rightly belonged to other and earlier forms of action.” [3]

     Excerpt from William Geldart’s Introduction to English Law (D.C.M. Yardley eds 9th ed.1984):

“By conversion of goods is meant any act in relation to goods which amounts to an exercise of dominion over them, inconsistent with the owner’s right of property. It does not include mere acts of damage, or even an asportation which does not amount to a denial of the owner’s right of property; but it does include such acts as taking possession, refusing to give up on demand, disposing of the goods to a third person, or destroying them.” [4]

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