"These publishers are predatory because their mission is not to promote, preserve, and make available scholarship; instead, their mission is to exploit the author-pays, Open-Access model for their own profit.” (Beall, 2010)
"Journals exploiting gold open access, providing no or non-sensible peer review, undercutting standard article processing charges, while frequently publishing rubbish" (Beall, 2012)
Beall, J. (2010). “Predatory” open-access scholarly publishers. The Charleston Advisor, 11(4), 10-17.
Beall, J. (2012). Predatory publishers are corrupting open access. Nature, 489(7415), 179-180.
Totally False: illegitimate journals created for profit. Historically even reputably companies like Elsevier have created truly false journals.
Pseudo-scholarly: Publications that claim peer review, impact factor, and editing, but do not actually do these things. They may have longevity and hold conferences.
Hijacked: Publications that try to deceive by imitating established titles.
Scam: Publications that take your money, but nothing is published.
Ojala, M., Reynolds, R., & Johnson, K. G. (2020). Predatory journal challenges and responses. The Serials Librarian, 78(1-4), 98-103.