◌̅

A horizontal line to be placed above other characters.

◌̅

1. Used in some languages to mark abbreviations.

   ΙΣ ΧΣ, a Greek abbreviation of Jesus Christ.

2. (mathematics) Drawn over repeating digits.

   ${\displaystyle 12\div 7=1.{\overline {714285}}=1.714285714285714285...}$

3. (geometry) Drawn over letters which represent a line segment.

   ${\displaystyle {\text{segment }}{\overline {AB}}{\text{ has the same length as segment }}{\overline {CD}}}$

4. (physics) Used to denote antiparticles.

   p (proton); p (antiproton)

5. (mathematics) Indicates the complex conjugate of a complex number.

   ${\displaystyle {\bar {z}}={\overline {x+iy}}={x-iy}}$

6. (statistics) Used to mark the mean of a sample.
7. (Roman numerals) Multiplies the value of a group of digits by one thousand.

   IV — four; IV — four thousand; IV — four million

8. See ¯ for the macron, which is a diacritical mark used in multiple languages.

• ¯ (“macron, a line drawn over a letter in some languages”)

• Roman numerals#Vinculum on Wikipedia.Wikipedia