Definition of "junk" []

• Discarded material, such as glass, rags, paper, or metal, some of which may be reused in some form. (noun)
• Informal Articles that are worn-out or fit to be discarded: broken furniture and other junk in the attic. (noun)
• Informal Cheap or shoddy material. (noun)
• Informal Something meaningless, fatuous, or unbelievable: nothing but junk in the annual report. (noun)
• Slang Heroin. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "~ One man's junk may be a genomic treasure -- Scientists have only recently begun to speculate that what`s referred to as “junk” DNA - the 96 percent of the human genome that doesn`t encode for proteins and previously seemed to have no useful purpose - is present in the genome for an important reason."
• "I did the polar bear swim today too – oh that was the coldest thing ever – it wouldn’t have been so bad except that there was this crazy wind on the beach, and these huge waves that brought all the junk on the sea floor up, and so when I got out I was covered in seaweed and junk…"
• "It is more than a tad ironic that John Stossel frequently used and even popularized the term "junk science" on "20/20," and I began to wonder if he was engaging in it himself."