Quadrisect means to divide something into four parts. The word is usually used to refer to dividing something equally into partitions.
quadrasect: to cut into 4 peiced (trisect=3, bisect=2)
If bisect means to cut in two, possibly quadrasect could mean to cut into four but I cannot be sure.
To divide into 4 parts. (trisect=3 parts, bisect=2 parts)