sororize
/sɔrəraɪz/Definitions
1. verb
to become or make a sister; to initiate into a sisterhood or sorority
“After joining the sorority, she decided to sororize her younger sister.”
2. noun
the act or process of becoming or making a sister; the initiation into a sisterhood or sorority
“The sororization ceremony was a memorable experience for the new members.”