• 孝行こうこう — filial devotion / dutiful gratitude
• 親孝行おやこうこう — filial devotion toward parents
• 不孝ふこう — lack of filial piety
• 忠孝ちゅうこう — loyalty and filial duty

This kanji combines 子 (child) and a simplified form of 老 (elder), evoking a child supporting an elder — the core image behind filial piety.