SOROR (plural sorors;colloquial) A sorority sister; a fellow member of one's sorority. This premium embossed journal is dedicated to the 350,000 plus members of Delta Sigma Theta Sorority, Incorporated. When a Delta says soror, she is saying to her sister, I love you. I’m here for you. I forgive you. I cherish you. Soror means sister but for Deltas, so much more.