They didn't seem to understand the 'gravity' [='seriousness'] of the situation.
He uttered the oath with proper 'gravity'. [='solemnity']
Its low 'center of gravity' makes the car very stable.
(..) you're gonna spit into this miniature toilet bowl. You have no bottom lip so you let it all fall out, say, ''Thank God for gravity.'' Now you want to sit back but you can't because hanging... from your bottom lip is a long line and you can't get it off your bottom lip. Oh, if you wanna be gross, (..)1983 Bill Cosby: Himself