故

1. Descriptive/Temporal: A former or erstwhile state, status, or relationship (e.g., 故人 "former acquaintance," 故都 "former capital").

2. Causal/Logical: The cause, matter, or reason behind an event; consequently, therefore.

• Modifying a noun: Denotes status or provenance.
• Introducing a clause: Acts as a conjunction signaling a conclusion derived from preceding premises. In this causal sense, it functions as a bridge and does not require a pairing particle to signal the conclusion.

• vs. 古 (gǔ): 故 refers to a prior state relative to the present, whereas 古 refers to antiquity or a distant era.
• vs. 舊 (jiù): 故 denotes situational or relational displacement; 舊 typically implies physical wear, decay, or habit.

In later texts and vernacular usage, the glyph developed senses of "intentional" or "on purpose" (e.g., 故意), though this is generally absent in early classical passages.

When the glyph precedes a noun, prioritize the sense of "former/previous." When it introduces a clause following premises, prioritize "therefore" or "for this reason."