Etymology

Unclear. The initial gu may be cognate with 御 ‎(go, “honorific”), but it is problematic in that the only honorary prefixes found in Omoro Sōshi are 御 ‎(mi) and 御 ‎(o). Suku may be related to しけ ‎(shike, “a holy place”) or cognate with 塞 ‎(soko, “fortress”). While written with the kanji for "castle", textual and cultural evidence suggests that the initial primary meaning was a holy place.