- 1: one that steals especially stealthily or secretly; also : one who commits theft or larceny
- 2: one who takes portable property from another without the knowledge or consent of the latter, converting it to his own use; one who steals.
In criminal law, theft is the illegal taking of another person's property without that person's freely-given consent. The word is also used as an informal shorthand term for some crimes against property, such as burglary, embezzlement, larceny, looting, robbery, shoplifting, fraud and sometimes criminal conversion. In some jurisdictions, theft is considered to be synonymous with larceny; in others, theft has replaced larceny.
The actus reus of theft is usually defined as an unauthorized taking, keeping or using of another's property which must be accompanied by a mens rea of dishonesty and/or the intent to permanently deprive the owner or the person with rightful possession of that property or its use.
For example, if X goes to a restaurant and, by mistake, takes Y's scarf instead of her own, she has physically deprived Y of the use of the property (which is the actus reus) but the mistake prevents X from forming the mens rea (i.e., because she believes that she is the owner, she is not dishonest and does not intend to deprive the "owner" of it) so no crime has been committed at this point. But if she realises the mistake when she gets home and could return the scarf to Y, she will steal the scarf if she dishonestly keeps it. Note that there may be civil liability for the torts of trespass to chattels or conversion in either eventuality.