* Grave: (adj.) serious, solemn, important
* Gravity: (n.) the force that attracts all objects towards one another; seriousness, importance
* Gravitate: (v.) to be drawn to something, to move towards something
* Gravitation: (n.) the force of attraction between objects
* Gravid: (adj.) pregnant, bearing young
* Grave: (n.) a place where a dead body is buried
* Graveyard: (n.) a place where dead people are buried
* Graven: (adj.) carved, engraved
* Gravitas: (n.) seriousness, dignity, importance
* Gravidity: (n.) pregnancy
* Gravitometer: (n.) a device for measuring gravity
* Gravimetric: (adj.) relating to the measurement of gravity
Let me know if you'd like any more words with this root!