Answer:
The word "Goddess" refers to freedom, which is part of the main theme of this poem.
Step-by-step explanation:
In this poem by Phillis Wheatley, the fight for freedom led by General Washington can be seen as the main theme.
The author of the poem uses the word Goddess to emphasize this meaning, because that is what freedom is: a great "Goddess", the one who frees us and lets us live in peace.
Let's look at the following quote from the poem:
Proceed, great chief, with virtue on thy side,
Thy ev'ry action let the Goddess guide.
A crown, a mansion, and a throne that shine,
With gold unfading, WASHINGTON! Be thine.