Both an interjection meaning 'Oh that!' or 'Would that!' (expressing longing), and a personal name borne by Sheshan's daughter in Judah's genealogy (1 Chronicles 2:31).
The dual nature of Achelai -- a name and a cry of holy longing -- reflects Scripture's saturation with holy desire: creation groaning (Romans 8:22), the Psalmist thirsting (Psalm 63:1), and the church's cry 'Come, Lord Jesus!' (Revelation 22:20). God honors the longing heart.