(The name of) a former constellation of the southern hemisphere, the Royal Oak, created out of stars that were part of the former constellation Argo. Formerly also (in form Roboris Caroli) †used as a postpositive in the names of stars belonging to this constellation (obsolete).
The name was not widely accepted and was rejected by Lacaille in his more comprehensive mid-18th-cent. mapping of the stars of the southern hemisphere.
Robur Carolinum/ˌrəʊbə karəˈlʌɪnəm/ /ˌrəʊbə karəˈliːnəm/
Early 18th century; earliest use found in Robert Morden (d. 1703), maker of maps and globes. In some forms from post-classical Latin Robur Carolinum (E. Halley Catalogus stellarum australium; from classical Latin rōbur + post-classical Latin Carolinum, neuter of Carolinus of or relating to Charles from Carolus Charles + classical Latin -īnus, in allusion to the Royal Oak.