Passing-off: to misrepresent that one's business is that of, or connected with another, in a way likely to cause damage.
"A misrepresentation made by a trader in the course of trade to prospective customers of his or ultimate consumers of goods or services supplied by him, which is calculated to injure the business or goodwill of another trader (in the sense that this is a reasonably foreseeable consequence) and which causes actual damage to a business or goodwill of the trader by whom the action is brought or will probably do so."
That, from a House of Lords (England) decision, 1979 AC 731, as cited in Erven Warnink Besloten Vennootschap v. J. Townend & Sons, NHL v Pepsi 42 CPR 3d (1992) 390 (BCSC).
From Prosser, The Law of Torts (1971), as cited in Consumers Distributing Co. v. Seiko Time Canada Ltd.  1 SCR 583:
"(The ) making of some false representation to the public, or to third persons, likely to induce them to believe that the goods or services of another are those of the plaintiff. This may be done, for example, by counterfeiting or imitating the plaintiff's trade mark or trade name, his wrappers, labels or containers, his vehicles, the badges or uniforms of his employees, or the appearance of his place of business.
"The test laid down in such cases has been whether the resemblance is so great as to deceive the ordinary customer acting with the caution usually exercised in such transactions, so that he may mistake one for the other."
Also, in 2006, Canada's Supreme Court opined, in Mattel USA v 3894207 Canada Inc  1 SCR 772, that:
"In an action for passing off, it would have been necessary for the appellant to show that the respondent restauranteur intentionally or negligently misled consumers into believing its restaurant services originated with the appellant and that the appellant thereby suffered damage."
In Reckitt & Colman Products Limited v. Borden Inc. & Ors, a 1990 decision of the House of Lords (at 1990 RPC 341), the tort of passing-off was said to include:
"The law of passing off can be summarised in one short general proposition - no man may pass off his goods as those of another.
"More specifically, it may be expressed in terms of the elements which the plaintiff in such an action has to prove in order to succeed. These are three in number.
"First, he must establish a goodwill or reputation attached to the goods or services which he supplies in the mind of the purchasing public by association with the identifying "get-up" (whether it consists simply of a brand name or a trade description, or the individual features of labelling or packaging) under which his particular goods or services are offered to the public, such that the get-up is recognised by the public as distinctive specifically of the plaintiff's goods or services.
"Secondly, he must demonstrate a misrepresentation by the defendant to the public (whether or not intentional) leading or likely to lead the public to believe that goods or services offered by him are the goods or services of the plaintiff. Whether the public is aware of the plaintiff's identity as the manufacturer or supplier of the goods or services is immaterial, as long as they are identified with a particular source which is in fact the plaintiff. For example, if the public is accustomed to rely upon a particular brand name in purchasing goods of a particular description, it matters not at all that there is little or no public awareness of the identity of the proprietor of the brand name.
"Thirdly, he must demonstrate that he suffers or ... that he is likely to suffer, damage by reason of the erroneous belief engendered by the defendant's misrepresentation that the source of the defendant's goods or services is the same as the source of those offered by the plaintiff."
A very similar action lies in regards to s. 7 of the Canadian Trade-Mark Act, often plead at the same time as a passing-off action, and which read as follows (2010):
"No person shall
(a) make a false or misleading statement tending to discredit the business, wares or services of a competitor;
(b) direct public attention to his wares, services or business in such a way as to cause or be likely to cause confusion in Canada, at the time he commenced so to direct attention to them, between his wares, services or business and the wares, services or business of another;
(c) pass off other wares or services as and for those ordered or requested;
(d) make use, in association with wares or services, of any description that is false in a material respect and likely to mislead the public as to
(i) the character, quality, quantity or composition,
(ii) the geographical origin, or
(iii) the mode of the manufacture, production or performance
of the wares or services; or
(e) do any other act or adopt any other business practice contrary to honest industrial or commercial usage in Canada."
French: commercialisation trompeuse.