Bait And Switch Definition

bāt'nswich
noun
A fraudulent advertising claim or sales offer for a product or service that is not available or not for sale at the stated price, made with the intention of luring customers who are then offered something else or forced to spend more money to get the same thing.
American Heritage
A deception based on a false claim or enticement that proves to be disappointing.
American Heritage

An unscrupulous and sometimes illegal sales technique, in which an inexpensive product is advertised to attract prospective customers who are then told by sales personnel that the inexpensive product is unavailable or of poor quality and are instead urged to buy a more expensive product.

Wiktionary

(by extension) Any similar deceptive behavior, especially in politics and romantic relationships.

Wiktionary
adjective
Of, related to, or employing an illegal or unethical sales technique in which a seller lures customers by advertising an often nonexistent item at a bargain price and then attempts to switch their attention to more expensive items.
Webster's New World
Relating to use of bait and switch (offering one attractive exchange initially, but not honoring the offer) in business, politics, and elsewhere.
Wiktionary
verb
The practice of advertising a product or service at a low price to bring customers into a store and, once they are there, urging them to buy a more expensive product or service by disparaging the original item or by saying that it is no longer available. This is illegal in most states, especially when the original product or service was not available at the time it was advertised.
Webster's New World Law