From Old English 'hlūd' (noisy), from PIE *ḱlew- (to hear) — something loud is literally 'heard.'
Producing or capable of producing much noise.
From Old English 'hlūd' meaning 'loud, noisy,' from Proto-Germanic *hlūdaz, from PIE *ḱlew-tó- meaning 'heard,' from *ḱlew- (to hear). Something loud is literally 'heard' — perceivable by the ear. Key roots: *ḱlew- (PIE: "to hear").