How many words start with GRO?

20, from 5 letters up to 5. All of them are on this page.

What is the highest scoring word that start with GRO?

GROSZ at 15 points in Scrabble, and GROSZ at 16 in Words With Friends, because the two games score the tiles differently.

GROAN, GROAT, GRODY, GROGS, GROIN, GROKS, GROMA, GRONE, GROOF, GROOM and 10 more on this page.

20 of them: GROAN, GROAT, GRODY, GROGS, GROIN, GROKS, GROMA, GRONE, GROOF, GROOM and more.

There are 20 of them. The highest scoring is GROSZ at 15 points in Scrabble, and the set averages 8.1.

Most common words first, then the rest A to Z.

The most familiar words on this page and what they mean. Tap any word for its full entry, score and anagrams.

GROUP noun any number of entities (members) considered as a unit
GROSS adjective before any deductions
GROVE noun a small growth of trees without underbrush
GROWN adjective (of animals) fully developed
GROWS verb form of GROW: pass into a condition gradually, take on a specific property or attribute
GROOM noun a man participant in his own marriage ceremony
GROAN noun an utterance expressing pain or disapproval
GROAT noun a former English silver coin worth four pennies
GROGS noun form of GROG: rum cut with water
GROIN noun the crease at the junction of the inner part of the thigh with the trunk together with the adjacent region and often including the external genitals

Definitions from Open English WordNet, CC BY 4.0.

All of them: Word lists.