Gravitas

A serious or dignified demeanor: “Our national father figure needs gravitas, [but] he's pitched himself as the kid brother”

gravitas

n : formality in bearing and appearance; "he behaved with great dignity"

It’s a Latin word, a noun formed from the adjective gravis, heavy. English borrowed the Latin word via French as gravity at about the beginning of the sixteenth century. Then, it had much the same sense as gravitas now has: weight, influence, or authority. It could also refer to some matter that was grave (which comes from the same Latin source) or to a solemn dignity, a sobriety or seriousness of conduct. A weighty word indeed, the opposite of levity, a lightness that causes bodies to rise, a tendency for people to exhibit lightweight attitudes.

It was the natural philosophers of the early seventeenth century who began to lay the ground for the introduction of gravitas by borrowing the word gravity for that mysterious force that generates weight. After Isaac Newton, gravity became so closely attached to the concept that it slowly lost some of its associations with the older senses. Writers from the 1920s onwards began to use gravitas instead, as a direct reference to the classical Latin authors like Cicero who employed it in much the same way. It is very noticeable that it was for some decades the preserve of portentous leader writers, careful always to write it in italics to tell the reader that, yes, we know it’s a foreign word. But it looked so much more intellectual than gravity and was so much better for communicating that sense of classical sobriety that its appeal was irresistible.