Wiktionary:Spam

There are two types of spam on Wiktionary. These are advertisements masquerading as dictionary entries and external link spamming.

Advertisements masquerading as dictionary entries
All Wiktionary entries must follow the criteria for inclusion. Entries that are considered advertisements act as solicitations for a business, product or service, or are public relations pieces designed to promote a company or individual. All trademarks and companies must follow Wiktionary's policy on company names and brand names. Spam entries are usually noted for sales-oriented language and external links to a commercial website.

Blatant examples of advertising masquerading as dictionary entries can be immediately deleted by administrators, or tagged for deletion by adding to the entry. Other advertisements posted on Wiktionary can be dealt with by listing them on Requests for deletion. On some occasions, the content can be removed temporarily on the basis of a suspected copyright violation, since the text is often copied from another website and posted anonymously.

External link spamming
Adding external links to a dictionary entry or user page for the purpose of promoting a website or a product is not allowed, and is considered to be spam. External links must help to explain the definition of the word, or give details on its etymology and background. Although the specific links may be allowed under some circumstances, repeatedly adding links will in most cases result in all of them being removed.

Inclusion of one spam link is not a reason to include another
Many times users can be confused by the removal of spam links because other links that could be construed as spam have been added to the article and not yet removed. The inclusion of a spam link should not be construed as an endorsement of the spam link, nor should it be taken as a reason or excuse to include another.