hydrocortisone UK /ˌhʌɪ.dɹə(ʊ)ˈkɔː.tɪ.zəʊn/US /ˌhaɪ.dɹoʊˈkɔɹ.tɪˌsoʊn/ noun1 •Name used for cortisol, a glucocorticoid steroid hormone, when used as a medication. Used to treat e.g. inflammation resulting from rheumatism and eczema. formshydrocortisones