⊖ is the Unicode character "circled minus" (U+2296). ⊖ is also known as the

Plimsoll symbol The waterline is the line where the hull of a ship meets the surface of the water. Specifically, it is also the name of a special marking, also known as an international load line, Plimsoll line and water line (positioned amidships), that indi ...

. ⊖ may refer to: * Symmetric difference, the set of elements which are in either of two sets but not in their intersection *

Erosion (morphology) Erosion (usually represented by ⊖) is one of two fundamental operations (the other being dilation) in morphological image processing from which all other morphological operations are based. It was originally defined for binary images, later bei ...

, one of the fundamental operations in morphological image processing * A function for reversal and rotation in the

APL programming language APL (named after the book ''A Programming Language'') is a programming language developed in the 1960s by Kenneth E. Iverson. Its central datatype is the multidimensional array. It uses a large range of special graphic symbols to represent mos ...

* Symbol for the

Escape character In computing and telecommunication, an escape character is a character (computing), character that invokes an alternative interpretation on the following characters in a character sequence. An escape character is a particular case of metacharac ...

in ISO 2047 * Used to designate a thermodynamic quantity in the

Standard state In chemistry, the standard state of a material (pure substance, mixture or solution) is a reference point used to calculate its properties under different conditions. A superscript circle ° (degree symbol) or a Plimsoll (⦵) character is use ...

in chemistry * Part of the notation for

Standard enthalpy of reaction The standard enthalpy of reaction (denoted \Delta_ H^\ominus or \Delta H_^\ominus) for a chemical reaction is the difference between total reactant and total product molar enthalpies, calculated for substances in their standard states. This can i ...

, as in Δ''H''^⊖_reaction

See also