衡定 (héng dìng) is a formal, written verb meaning 'to determine definitively' or 'to fix'—especially in contexts requiring objectivity, stability, or authoritative judgment. The character 衡 (héng) originally means 'balance' or 'scale', evoking fairness and measured assessment; 定 (dìng) means 'to decide', 'to settle', or 'to fix'. Together, they convey the idea of arriving at a stable, impartial, and final determination—often after careful evaluation or comparison. This word is rarely used in casual speech and appears most frequently in academic, legal, technical, or policy-related texts.

It commonly collocates with abstract nouns like 标准 (standard), 原则 (principle), 价值 (value), or 范围 (scope). Unlike simpler verbs like 决定 (juédìng) or 确定 (quèdìng), 衡定 implies a higher degree of deliberation, calibration, and normative authority—suggesting that the outcome is not merely chosen but justly weighed and firmly established.