what is the difference between "jolly" and "joy"
for example :a jolly fox means a joy fox?

Question

what is the difference between "jolly" and "joy"
for example :a jolly fox  means a joy fox?

Answer

Beethoven didn't write "Ode to Jolly".

OK, seriously, the words are not related at all.  "Jolly" refers to a happy or merry character, and "joy" is a feeling of delight, pleasure or even celebration.

Answer

While jolly and joy both mean to be happy or happiness respectively. One is a adjective (jolly) and one is a noun (joy).

You would need to use joyful (adjective form of joy) to describe the fox. - A joyful fox.

Then they would mean the same thing.