主体
しゅたい · shutai · JLPT N1 · noun
subject
主 (main) + 体 (body/entity): the main body of a sentence, its subject
主 means main or master, and 体 means body or form. Together they name the main constituent a sentence is about: the subject.
主 — flame/lamp on top of a stand 王
Originally a pictograph of a lamp with a flame on top of its stand, representing the lord or master of the household who tended the fire. The meaning extended from 'lamp/host' to 'master, owner, main, principal'. The character 炷 (wick) preserves the original 'lamp' sense.