Definition of "gravitas" from The Free Dictionary:
Seriousness or solemnity in demeanor or treatment.
In usage, the word gravitas refers to a person whose actions, behavior or personality exudes decorum or sobriety. It can also be used to describe the substance or weightiness of something.
Synonyms for gravitas:
dignity
gravity
sobriety
Gravitas Sentence Examples:
The director told the actress that she would have to play her character with great gravitas if she wanted to come across as convincing.
The only reason that people have faith in him is because he has the gravitas of a person who can take big decisions.
She radiates the gravitas of a woman who knows how to deal with people and handle complex situations efficiently.
Lost for Words? Here Are Some Tips to Remember About Improving Memory, shared by VOA Learning English.