Gravity, weightiness, solemnity, seriousness - but also pregnancy and sickness (both heavy matters).
Yes, in Latin, but they mean in English. There's more meanings for the Latin word than for the English word, that came directly from Latin (it's uncommon).
The Latin word gave "gravide" (in gestation) and "gravidique" in French, medical term meaning "gestational". (gravidité, English gravidity)
And Gravité -> Gravity for the Physical Earth force.
For sickness, I think it rather mean "a feeling of heaviness in body organs" (Gaffiot), as it's related with gravity/weightness/physical gravity force.
It's also "gravitas senilis", meaning the figurative "weightness" of the old age.
The link with the fact to be pregnant is here:
"Gravide" from Latin gravida (= pregnant), from gravis (= heavy).
So, everything in this word is related to the idea of "weight". For the solemnity, it's not the case, so I don't know how "weight" became "solemnity".
In English, we love to slip into foreign languages whenever we feel that a semantic association to a foreign language might be useful. For example, we'll use a Latin word to sound "intelligent"; a French word to sound "sophisticated", a German word to sound "philosophical"... E.g., "Although the CEO -- a true paterfamilias of the company -- inspired respect and awe among his employees by virtue of his stately gravitas and a certain je ne sais quoi that always seemed to guide him to the right business decisions, he had been weighed down with Weltschmertz of late, and all but the most insouciant among us could tell that he had lost a step."