Ào nǎo (懊恼) is a compound word expressing deep, inward-facing regret or remorse—often accompanied by frustration or self-reproach. The first character 懊 (ào) conveys sorrowful reflection, while 恼 (nǎo) adds the sense of mental distress or vexation; together, they emphasize an emotional state where one feels troubled by past actions or missed opportunities. It’s commonly used in written and formal spoken Chinese, especially when describing personal disappointment or moral unease.

This word carries a stronger, more introspective tone than simpler synonyms like 后悔 (hòuhuǐ, 'to regret')—it suggests lingering discomfort rather than momentary regret. It frequently appears in literature, essays, and reflective speech, often followed by clauses explaining the cause (e.g., '懊恼自己没好好珍惜'). While it can function as both a noun ('a feeling of remorse') and a verb ('to feel remorse'), it rarely takes aspect markers like 了 or 过 in casual speech, preserving its literary weight.