This precise temporal measurement appears only in Revelation's apocalyptic vision, describing a profound silence in heaven. The compound joins 'half' (ἡμι-) with 'hour' (ὥρα) to create an exact duration. In the dramatic sequence of Revelation 8:1, this half-hour silence follows the opening of the seventh seal, creating a moment of cosmic suspense before the trumpet judgments. The specificity of the time marker adds to the prophetic precision of John's vision.