ology UK /ˈɒ.lə.d͡ʒɪ/US /ˈɑ.lə.d͡ʒi/ noun1 •(informal) Any branch of learning, especially one ending in “-logy”.Dr Ehrhart protested no country under the sun equalled Portugal for curiosities in mineralogy, theology, and wineology – which ology he was convinced was the best of them all. — 1786 formsologies