mid-14c., "sound repeated by reflection," from Latin echo, from Greek echo, personified in classical mythology as a mountain nymph who pined away for love of Narcissus until nothing was left of her but her voice, from or related to ekhe "sound," ekhein "to resound," from PIE *wagh-io-, extended form of root *(s)wagh- "to resound" (source also of Sanskrit vagnuh "sound," Latin vagire "to cry," Old English swogan "to resound"). Related: Echoes. Echo chamber attested from 1937.
1550s (intrans.), c. 1600 (trans.), from echo (n.). Related: Echoed; echoing.