loss of words
person 1: why don't you ever talk to me anymore? do you not want to be my friend? person 2: sorry, i've been at a loss of words lately
"a phrase used as an excuse to not say anything
"person 1: why don't you ever talk to me anymore? do you not want to be my friend? person 2: sorry, i've been at a loss of words lately" What is the definition of "loss of words"?