Often used as a synonym for Sodium thiosulphate or for motion picture film fixer. The name of a fixing bath made from ammonium or sodium thiosulfate, other chemicals, and water.
Hypo Eliminator
Chemical used to clear fixer from an emulsion to shorten washing time or to improve archival keeping properties.
References
Case, D., 1985, Motion Picture Film Processing, Media Manuals, Focal Press, London, Boston