There are 8 words that start with 'geost'.
| geostrategy | geostrophic |
| geostrategic | geostationary |
| geostrategies | geostrategist |
| geostrategists | geostrophically |
Note: These 8 words that start with 'geost' are found from the USA & Canada version of the tournament Scrabble word list.