Celsius, or Celsius scale, is named after its inventor, Anders Celsius. Centigrade—an adjective only—is the early nineteenth century alternative to Celsius and means, literally, hundred steps (from Latin centum + gradus). Although you may still see centigrade used to describe the scale, Celsius is far more common and should be preferred in all situations. Prefer It is forty degrees Celsius and The Celsius scale to It is forty degrees centigrade and The centigrade scale.