nAntichlor(Chem) Any substance (but especially sodium hyposulphite) used in removing the excess of chlorine left in paper pulp or stuffs after bleaching.
Century Dictionary and Cyclopedia
nantichlorIn bleaching, any substance or means employed to remove or neutralize the injurious effects of the free chlorine left in cotton, linen, or paper which has been bleached by means of alkaline hypochlorites, as chlorid of lime, etc. The neutral and acid sodium sulphites were first used, but they are now superseded by sodium hyposulphite or thiosulphite, which is both cheaper and more efficacious. This antichlor forms, with the chlorine in the cloth, etc., sodium sulphate and chlorate, which are easily removed by washing.
Chambers's Twentieth Century Dictionary
nAntichloran′ti-klōr a substance used in the making of paper to free the pulp from the injurious after-effects of chlorine.