From G2152 (eusebēs, devout). To act piously, show reverence and practical devotion. Used for worship of God and honoring family.
Eusebeō bridges worship and ethics. In 1 Timothy 5:4, children are told to 'shew piety at home' — caring for parents is worship. This is radical: honoring your aging mother is as much eusebeia as singing hymns. The NT refuses to separate vertical devotion from horizontal duty.