⊖ is the Unicode character "circled minus" (U+2296). ⊖ is also known as the Plimsoll symbol. ⊖ may refer to: Symmetric difference, the set of elements which are in either of two sets but not in their intersection Erosion (morphology), one of the fundamental operations in morphological image processing A function for reversal and rotation in the APL programming language Symbol for the Escape character in ISO 2047 Used to designate a thermodynamic quantity in the Standard state in chemistry Part of the notation for Standard enthalpy of reaction, as in ΔH⊖reaction
See also Celtic cross Coptic cross Cross symbol Theta Ø (disambiguation) Circled plus (disambiguation) ⦵ (U+29B5, CIRCLE WITH HORIZONTAL BAR) Mathematical Operators (Unicode block)