Junk is:

• A Chinese sailing vessel, see junk (sailing).
• Unwanted items in a physical sense, like junk cars. Because junk cars are a source for scrap metal spare parts, they're often sold to a junk yard, where they are typically stacked (or strewn) about a large enclosure, sometimes guarded by a "junkyard dog".
• Junk mail.
• The phrase "junk" used as an exclamation can be used in a variety of ways. It can replace the commonly used "darn" in one instance. This use is not often heard but is becoming more and more frequently used. It is quick and to the point but also satisfying to say.
• If someone exclaims that they have been "junked" it means that they have been injured in some physical way.
• The phrase "junk it out" can mean one of two things. The first meaning being, "get out of town, man!" This interpretation is closely linked to, "No way!" When in a slightly more agitated mood it can be understood to mean, "shut up". The expression "junk it out" is commonly shortened in to, "junk it!" However, this phrase often gets confused with a "junket", or a press release for major motion picture.
• When the term is spelled, "junque" its refers to antiques. Antique shops are full of "junque" that people buy and sell to make a small profit. Such junque may include old porcelain dolls, beat up furniture, or tarnished silverware. All of these things are classy forms of your average "junk".
• Junk characters in electronic text can be caused by transmission errors (line noise) and often appear as groups of "strange" letters like punctuation or accented letters. A high percentage of letters outside the standard 26-letter English alphabet often indicates the presence of junk, thus leading to filtering strategies.
• The planet of Junk in the Transformers Fictional Universe is exactly that – a planet of junk.
• Heroin
• A man's genitals

See also:

• Junk food
• Junk food news
• Junk science
• Junkie