恆

Phono-semantic compound:

心 (마음 심) — semantic element: mind, inner state, feelings, intentions.

亘 (긍 / 선) — phonetic element giving the sound 항 and also meaning “to stretch, to span widely.”

Thus 恆 originally conveyed “a heart/mind that is steady and extended”—

steadiness, constancy, enduring nature.

Shuowen Jiezi (說文解字):

No separate entry for 恆, but 恒 appears:

「恒，常也。从心，亘聲。」

“恒 means ‘constant.’ Formed from 心 with 亘 as the phonetic.”

Semantic development:

Constancy / permanence — what remains unchanged.

Regularity / everydayness — “ordinary, usual, habitual.”

Stability of character — firmness, steadiness of mind or virtue, important in Confucian ethics.

Extension / reaching broadly — inherited from 亘 “to extend across,” “to reach widely.”

Moral/ethical meaning — unchanging virtue or consistent moral behavior.

In Korean, 恆/恒(항) appears in Sino-Korean compounds referring to constancy, permanence, regularity, and steady character.

Constancy / permanence:

恆常 (항상) — 늘 그러함; always; constantly

恆久 (항구) — 오래 지속됨; permanent; lasting

恆心 (항심) — 흔들리지 않는 마음; steadfastness; constancy

恆量 (항량) — 일정한 양; constant quantity

Stability / steadiness:

恆定 (항정) — 변하지 않음; fixed; stable

恆態 (항태) — 늘 일정한 상태; constant state

恆속 (항속) — 변함없는 속성; inherent, unchanging nature

Classical / literary:

恆道 (항도) — 변함없는 도리; constant moral path

恆德 (항덕) — 늘 한결같은 덕; constant virtue

恆久之志 (항구지지) — 오래 변치 않는 뜻; persevering will

Used in Korean philosophy, literature, science (constant quantity), and everyday compounds like “항상.”

Both 恆 and 常 mean “constant,” but:

恆 emphasizes unchanging internal continuity.

常 emphasizes frequency / usualness.

恆心 — steadfast heart

常心 — usual state of mind (less common)

恆 is foundational in Confucian moral discourse:

恆心 (steadfastness)

恆德 (constant virtue)

恆道 (unchanging Way)

Classical citations:

《論語·里仁》 (The Analects)

「君子恆道。」

“The gentleman maintains constancy in his way.”

《孟子·滕文公上》 (Mencius)

「行有不得者，皆反求諸己，其身正而天下治，恆之道也。」

“Whenever actions fail, look within oneself. When one’s person is upright, the world becomes ordered—this is the constant Way.”

《荀子·修身》 (Xunzi)

「恆德之本也。」

“Constancy is the root of virtue.”

《詩經·大雅》 (The Book of Songs)

「恆有不忍。」

“They constantly possess compassion.”

《後漢書·光武帝紀》 (Book of the Later Han Dynasty)

「法度恆存。」

“The laws and institutions remained constant.”

These citations anchor 恆 as moral constancy, steady character, and unchanging regularity.

恆 — traditional form

恒 — variant adopted as standard in Japan and PRC

In meaning and usage, both are the same.