For scholarly work Open Access (OA) means free, immediate, permanent online access to the full text of peer reviewed literature for anyone connected to the internet.
Other definitions:
SPARC: Scholarly Publishing and Academic Resources Coalition (200+ members are primarily academic and research libraries located in the U.S. and Canada)
EPrints (open-source digital repository platform developed at the University of Southampton)
Australasian Open Access Strategy Group (supported by ten Australian and eight New Zealand Institutions with a commitment to Open Access)
OpenSource.com (a community resource)
Other important organizations defining open access in academia:
OApen.org (The National Library of the Netherlands)
The notion of "predatory" publishing in OA has been around since 2009. The notion itself is controversial and has been challenged.
See Anderson, Rick. "Should we retire the term 'predatory publishing' "? the scholarly kitchen, May 11, 2015. https://scholarlykitchen.sspnet.org/2015/05/11/should-we-retire-the-term-predatory-publishing/. Accessed Oct. 19, 2016.