A binary operator symbol representing Hermitian conjugation in linear algebra and quantum mechanics, also used for footnotes.
Examples
Footnote reference in mathematical text
Let f(x)\dagger \text{ be the adjoint operator of } f(x)
Matrix adjoint notation
A\dagger = (\overline{A})^T \text{ denotes the conjugate transpose}
Marking a special case or condition
x = 2\dagger \text{ where }\dagger\text{ indicates the principal solution}