0 unable to speak because you are so angry, shocked, surprised, etc.: --
She was speechless with indignation.
1 temporarily unable to talk or to know what to say, esp. because of having strong feelings: --
For once the trade seems almost unanimous in its approval, and this is so astonishing that it leaves one virtually speechless.
Politicians may know, but, for once, the economists are speechless.
When we began our work, we were almost speechless at what we encountered.
I am often left speechless by the shirkers who come to my surgery and blatantly say that they cannot possibly work.
He was so angry that it left him speechless, because he never raised the state of the national health service.
I nearly said "speechless", but, obviously, that is not true tonight.
Is that because they have been rendered speechless by the sheer ugliness of the building?
The patter and the repartee flow and only on a rare occasion is one left speechless on a doorstep.