what does "bay" mean

You mean Haitian Creole word "bay"?

bay → to give

You will see the Haitian creole word "bay"written three different ways:
Bay, ba, & ban

"ban" comes before Haitian Creole pronouns "mwen" "m" "nou" & "n".
Example:
Li ban mwen yon liv. - He gives me a book.
Li ban m yon liv. - He gives me a book.
Li ban nou yon liv. - He gives us a book.
Li ban n yon liv. - He gives us a book.

"ba" comes almost exclusively before Haitian Creole pronouns "ou" "li" "yo".
Example:
Mwen ba ou yon liv. - I give you a book.
Mwen ba li yon liv. - I give her a book.
Mwen ba yo yon liv. - I give them a book.

Then,
You may use "ba" or "bay" most anywhere else.
Jezi bay lavi. - Jesus gives life.
Bay Joel liv la. - Give the book to Joel.
Revanj bay satisfaksyon - Revenge gives (brings) gratification
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