liquid paraffin UK /ˌlɪk.wɪd ˈpa.ɹəf.ɪn/US /ˌlɪk.wɪd ˈpɛɹ.əf.ɪn/ noun1 •A colorless, odorless oily liquid consisting of a mixture of hydrocarbons obtained from petroleum, used chiefly in medicine for treating constipation and especially formerly as a demulcent and solvent for nose and throat medication.