The latest TIME magazine (p23) has an interesting use of the word. The Secretary of the
Treasury has been criticized tor being too outspoken.
"It's not that he's bad, and not that he's dumb," says a New York banker who attended a
meeting with O'Neill last week. "It's just that he has no gravitas And once you
lose it, you can't get it back."

The meaning is clear enough. But let's hear some suggestion as to other ways of saying it. I
think it may be hard to improve on.

Edit: My dictionary definition is:
gravitas - a certain reserved dignity; propriety and good taste in behavior and speech, as of a leader or official

here's my favoritest orotund pundit Bill Buckley opining, "The key figure, of course, is Senator Nunn around whose judgments gravitas closes in like clouds gathering around a prophet."

gravitas - a certain reserved dignity; propriety and good taste in behavior and speech, as of a leader or official

I always understood it as meaning authority with a dash of seriousness, Bill.

Propriety and good taste are highly likely, but not mandatory.
This is probably a whimsical interpretation.

Alas, whatever the definition may be, it usually comes out being 'stuffy'.

Dear Byb: Stuffy means that you have displayed a dullness that makes you poor
company. The Secretary's problem is that he reveals ideas that the President
would prefer not made public.

in explaining his usage, Buckley defines it as "The kind of solemnity one associates with kings, bishops and wise men; used in Rome to designate the mien of thoughtful, civic-minded wise men." -- this is in agreemony with the "high seriousness" of MW10.

around whose judgments gravitas closes in like clouds gathering around a prophet."
Well, my Dear, I don't know about clouds, but around here, you have the gravitas. [bow]

At first sight the tall, stooped figure with the hawk-like features and bloodless
cheeks, the look of extreme gravitas, seems forbidding and austere, the abbot of
an ascetic order, scion of an imperial family who has foresworn the world.
--John Lehmann, "T.S. Eliot Talks About Himself and the Drive to Create," New
York Times, November 9, 1953

Wasn't there a novel about a group of distinguished professors, judges, and senators who were also gay. Gravitas Rainbow?

No, TEd. That's to be the sequel, not yet published. A Pynchon of pepper on your posterior.