ALLELU'IAH, noun [Heb. praise to Jah.] Praise to Jehovah; a word used to denote pious joy and exultation, chiefly in hymns and anthems. The Greeks retained the word in their praise to Io; probably a corruption of Jah. The Romans retained the latter word in their Io triumphe.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI