Please explain what it means by right-sided transverse process of l5 is partially sacralized?

Fusion at L5-S1: A there has been a fusion of the transverse process of L5 on the right to the sacrum.. A boney or calcified bridge has formed. This may be congenital or from the time of birth, or it may be associated with degenerative arthritis. The condition by itself is harmless unless it caused encroachment of an exiting nerve root at a neuroforamen or window where a nerve root exits the spinal canal.