Buses are often called "pullman" in Italy. For long time I thought it was because the pull men (and women) along the road, but instead it appears there are named after some George Pullman. Also in Italy, the loop highway around Rome is known as GRA, which stands for "Grande Raccordo Anulare" ("Big Annular Highway"), but that is just a backronym: originally it is also the surname of Eugenio Gra, the engineer who desig…
Related to "big annular": why does the Latin word for ring have a diminutive suffix ( -ulus ), even when it refers to big rings? Well, of course because anus came to refer to one very specific ring.
Let me just note that there are other words that descend from the Latin diminutive instead of the basic form. For example, "castrum" with its diminutive "castellum" became "castello" in Italian and "castle" in English, while the base form was retained only in toponyms (the suffix "chester" in English and "castro" in Italian). As for "anellus", I see no compelling reason to use the diminutive instead of the base form. I guess it's just an artifact of time (with a funny result: since Italian has again suffixes for diminutive and augmentative, we can use the words "castellino" and "castellone", literally a "little little castrum" and "big little castrum"; confusing!).