celsius

The term originates from the Latinized name of Swedish astronomer and scientist Anders Celsius (1701–1744), who proposed a temperature scale in 1742. While the scale was later inverted to its modern form (0° for freezing, 100° for boiling), his name became permanently attached to the unit of measurement. The adoption of a personal surname as a standard scientific term follows a common pattern in metrology, similar to 'fahrenheit' or 'volt'. The word entered international scientific vocabulary in the 19th century and is now a fundamental unit in the metric system.

The word 'celsius' is a loanword adopted as a single unit from the Latinized surname of the Swedish astronomer Anders Celsius. It does not contain productive morphemes in English that can be segmented based on its current spelling.