柱
Hashira
"Pillar" — the nine highest-ranked swordsmen of the Demon Slayer Corps. VIZ keeps the term romanized ("WATER HASHIRA: GIYU TOMIOKA"), one of the series' load-bearing untranslated words.
鬼殺隊
Demon Slayer Corps
The demon-hunting organization — literally the "demon-killing corps" — that Giyu serves as Water Hashira and Tanjiro joins on his advice.
水の呼吸
Water Breathing
Giyu's combat style — 全集中・水の呼吸, "Total Concentration: Water Breathing." Ten inherited forms; Giyu added an eleventh of his own.
凪
Dead Calm
The Eleventh Form Giyu invented — 凪, the nautical word for a windless, waveless sea. VIZ's DEAD CALM is the rare one-word poem that survives translation; see the Gem.