someone or something whose good qualities are hidden.

This film is one of those diamonds in the rough, a wonderful gem that almost no one has noticed.

Etymology: based on the idea that you cannot see the beauty of a diamond (= jewel) when it is rough (= not yet cut and filled with brightness)

• at the end of the day
• at the expense of
• at the expense of something
• at the hands of
• at the hands of someone
• at the helm
• at the helm of
• at the helm of something
• at the latest
• at the mercy of
• at the mercy of someone
• at the mercy of something
• at the moment
• at the most
• at the outside
• at the point of
• at the point of something
• at the ready
• at the ripe old age of
• at the ripe old age of something
• at the top of agenda
• at the top of lungs
• at the top of someone's agenda
• at the top of the agenda
• at the top of the ladder