艱

Originally a compound ideograph: 壴 — a drum (used in rituals or signals); 𦰩 — a person with bound arms, symbolizing restraint or suffering. This combination expressed the idea of being constrained, struggling, or enduring hardship.
Later interpretations (e.g., in Shuowen Jiezi) treated it as a phono-semantic compound, combining: 𦰩 — semantic component (hardship); 艮 — phonetic component (간 / jiān). The modern form stabilized in the seal script (小篆) stage.
Semantic development: - physical restraint and suffering; - hardship or distress; - general difficulty or adversity.

간난 (艱難) — hardship; difficulty

간고 (艱苦) — hardship; suffering

간신 (艱辛) — hardship; toil

艱 often appears in formal or literary compounds, emphasizing serious or enduring hardship. It carries a stronger nuance than simple “difficulty,” often implying struggle, endurance, and suffering.
Related characters: 難 — difficult

苦 — suffering; pain

困 — hardship; distress