Unique; S*I I have a feeling it's SUI
Advocate of Territory return: I**E*E****
Essence of matter: G**T
Encircling fortification: EN*E*N*E
Ancient Greek forehead bank TA***A
sui generis [(sooh-ee, sooh-eye jen-uh-ris)] A person or thing that is unique, in a class by itself: “She is an original artist; each of her paintings is sui generis.” From Latin, meaning “of its own kind.”