Noun

1. Assertions that have the appearance, but not the actuality, of scientific support.

   His testimimony was worse than science fiction, it was junk science.

2. A cluster of assertions, publications, and experts that have the appearance, but not the actuality, of a scientific specialty.
   • 2006, Roger W. Shuy , Linguistics in the Courtroom: A Practical Guide, page 99

     Our field falls neither in the category of immediately acceptable DNA experts at one end of the spectrum nor in the category of the immediately unacceptable so-called junk sciences at the other end.

Usage notes

• A label used to attempt to discredit expert testimony and claimed scientific support for positions taken on some matters of public policy.
• Not usually applied to the scientific implausibility of elements of science fiction.