Yarn weight issues

I recently bought some Aran yarn, intending to buy worsted weight yarn. Can I still use this for my hat project that calls for worsted without changing the pattern? What does Aran mean? Is it a weight? Thanks for any help. :heart:

Aran is slightly heavier than worsted. You should swatch, since you may have to use a smaller needle, but it should be fine.

Thanks for the help