flat (adjective) flat: level, smooth
Sinonime: cavernous, clangorous,
dull, echoing,
flat,
ghostly,
low, muffled,
mute, muted, resounding, reverberant, ringing, roaring, rumbling, sepulchral, sounding, thunderous, toneless,
vibrant, vibrating
Antonime: high,
light,
soft