‾

‾	U+203E, ‾ OVERLINE

General Punctuation

̅	U+0305, ̅ COMBINING OVERLINE

Combining Diacritical Marks

Translingual

A horizontal line to be placed above other characters.

‾

(mathematics) Drawn over repeating digits.
$12\div 7=1.{\overline {714285}}=1.714285714285714285...$
(geometry) Drawn over letters which represent a line segment.
${\text{segment }}{\overline {AB}}{\text{ has the same length as segment }}{\overline {CD}}$
(mathematics) Indicates the complex conjugate of a complex number.
${\bar {z}}={\overline {x+iy}}={x-iy}$
See ¯ for the macron, which is a diacritical mark used in multiple languages.