σιωπάω
siōpáō
see-o-pah'-o
from a Greek word not found in the New Testament σιωπή (silence, i.e. a hush; properly, muteness, i.e. involuntary stillness, or inability to speak; and thus differing from σιγή, which is rather a voluntary refusal or indisposition to speak, although the terms are often used synonymously); to be dumb (but not deaf also, like κωφός properly); figuratively, to be calm (as quiet water).

KJV translates as: dumb, (hold) peace