the word.

gravity-

1. the force of attraction that moves or tends to move bodies towards the centre of a celestial body, such as the earth or moon.

2. specific gravity the property of being heavy or having weight

3. seriousness or importance, esp. as a consquence of an action or opinion

4. manner or conduct that is solemn or dignified

origin-

1509, "weight, dignity, seriousness," from L. gravitatem (nom. gravitas) 'weight,heaviness, pressure," from gravis "heavy". The scientific sense of "force that gives weight to objects" first recorded 1641. Gravitate is first recorded 1692