gracia

Gracia is about shape and motion. It describes a body, a gesture, a dancer, an animal, a building, anything whose lines are light and well proportioned and whose movement costs no visible effort. It is close to bela but narrower: bela is a verdict on beauty in general, gracia is specifically about slenderness and ease.

Speakers of Spanish, Portuguese and Italian have to unlearn something here. Gracias, grazie and graça are all in the "thanks, favour, divine grace" family, and Esperanto put that family somewhere else entirely: thanks is danko, favour is favoro, divine grace is graco, and a joke is ŝerco. None of them is gracia. If you say Gracia! to a shopkeeper you have called them slender.

The word building is ordinary. Gracio is gracefulness as a quality, malgracia is clumsy or ungainly, and gracile in the sense of "slenderly" belongs to the near-neighbour root gracila, which some writers keep strictly for thinness of build. Most authors treat gracia and gracila as an overlapping pair and reach for whichever sounds better in the line.