Unable to find words or knowing what to say, often because of surprise, shock, or confusion.

निरुत्तर, बोलने के लिए शब्द नहीं मिलना

English Usage: When she received the unexpected award, she was at a loss for words.

Hindi Usage: जब उसे अप्रत्याशित पुरस्कार मिला, तो वह अवाक रह गई।