適

Phono-semantic compound:

辵 (쉬엄쉬엄갈 착) — semantic component, indicating movement or going

啇 (밑동 적 / 장사 상) — phonetic component giving the sound dí / zhí / jeok

辵 + 啇 → 適

Originally meant “to go to the place that matches,” hence “to fit,” “to be appropriate.”

In Korean, only the meaning “fitting, appropriate” remains productive.

適合 (적합) — to fit, to match

適當 (적당) — appropriate, suitable

適時 (적시) — timely

適用 (적용) — to apply, to be applicable

適性 (적성) — aptitude, suitability

《論語·里仁》 (Analects, “Li Ren”)

「君子適道，小人適利。」

“The gentleman goes toward (follows) what is right; the petty man goes toward profit.”

適 = “to go toward,” “to incline to.”

《孟子》 (Mencius)

《孟子·盡心下》

「適然後言。」

“Only after it is fitting, then speak.”

適 = “proper, appropriate.”

《莊子·逍遙遊》 (Zhuangzi, "Free and Easy Wandering")

「適彼樂土，而不知其所以然。」

“(He) goes to that land of ease, not knowing how it is so.”

適 = “to go to.”

《老子·第六十五章》 (variant citation seen in commentaries)

「知足不辱，知止不殆，可以長久適道。」

“…one can long remain in harmony with the Way.”

適道 = “to accord with the Dao.”

In Buddhist Chinese, 適 often expresses accord / suitability:

《大智度論》 (The Great Treatise on Perfection of Wisdom)

「隨其根性，適所應度。」

“According to their capacities, (the Buddha) teaches them in the way suitable for their liberation.”

適 = “suitable, fitting.”

In literature (文學):

《史記·刺客列傳》 (Records of the Grand Historian)

「士皆適從其志。」

“The knights all followed (went according to) their own will.”

《世說新語·言語》 (A New Account of Tales of the World)

「言辭清適。」

“His speech was clear and fitting.”