be at a loss

be at a loss

to not know what to do or say (usually + to do sth) He won't accept financial help from me so I'm at a loss to know what to do. For once I found myself completely at a loss for words. (= I did not know what to say)
See also: loss
References in classic literature ?
There is no doubt about that," replied the major; "and as we shall have to employ an immense quantity of metal, we shall not be at a loss for choice.