底

Phono-semantic compound:

底 = 广 (“house, space, structure”, semantic) + 氐 (“base, foundation”, phonetic)

广 (엄) — semantic element indicating a spatial area or structural boundary

氐 (저) — phonetic element; also originally meant “foundation, low/base,” supporting the semantic idea of “bottom”

Thus 底 literally represents “the base or bottom part of a structure.”

In early Chinese, 底 referred to the bottom of a dwelling or the foundational part of an object, and later broadened to abstract senses such as “essence,” “root,” and “after all.”

Spatial, bottom, base:

底部 (저부) — bottom part; base section

底層 (저층) — bottom layer; lower stratum

根底 (근저) — foundation, basis

Fundamental / essential:

底意 (저의) — hidden intention; underlying meaning

底本 (저본) — archetype; original manuscript

底蘊 (저운) — deep substance, underlying richness

Logical / abstract:

徹底 (철저) — thorough; exhaustive

到底 (도대체; 도저히)— “after all,” “in the end,” “ultimately”

— Sino-Korean uses Chinese adverbial sense

Interrogative / rhetorical (classical):

底事 (저사) — what matter?

底人 (저인) — what person? who? (rare, classical translation contexts)

In modern Chinese:

• 底 (dǐ) widely used as “bottom”: 底片, 底部, 海底

• 底 (dǐ) also forms adverbs: 到底 (“after all”), 究底 (classical “to investigate thoroughly”)

Distinction from 氐:

氐 originally meant “low, base,” and is phonetic here.

底’s meaning expanded while 氐 kept narrower functions (including as an ethnonym in Chinese history: the Di people).

Classical citations:

《左傳·僖公三十三年》 (Zuo Zhuan)

「夫民，神之主也，而可底乎？」

“The people are governed by the spirits — how could they be oppressed to the bottom?” — 底 = “to the bottom,” “to the extreme.”

《孟子·離婁下》 (Mencius)

「盡心知性，則知天矣。存心養性，所以事天也；殆庶幾乎！其底也。」

“Exhausting the mind to know one’s nature is to know Heaven. Preserving the mind and nurturing one’s nature is serving Heaven — almost so! This is its very essence” — 底 = essence, fundamental point.

《論語·學而》 (The Analects, Book 1)

「其為人也，發憤忘食，樂以忘憂，不知老之將至云爾。」（後世註解中多用“底意”）

"He was a man who, when engrossed in study, forgot to eat; when happy, forgot his worries; and was unaware that old age was approaching."

(Later commentary uses 底意 = “fundamental meaning,” “core intent.”)

《莊子·天下篇》 (Zhuangzi)

「是其所底也。」

“This is where it ultimately ends” — 底 = final outcome, end-point.