What does it mean when it's said that you're bones have fused or epiphyseals have closed? does that mean you can't grow taller anymore?

Done with growth: There are areas at the end of your bones when you are a kid and early teenager called the epiphysis. This is the area of the bone where growth takes place. During puberty, these areas begin to get smaller - we call that closing or fusing. Once that happens completely, there is no longer any area where further growth can occur and you have reached your final height.