Indicates special admiration or praise for someone or something exceptional. His dedication to his work is one in a million; he's truly unparalleled.
Pro Tip 2/3
Emotional Impact
Often used to express strong affection or to compliment someone dear to you. To me, you're one in a million; there's no one else like you.
Pro Tip 3/3
Not Literal
It's a figure of speech, not a real statistic; signals uniqueness beyond measure. A friend like her is one in a million; it's not like I meet people like her every day.