something that stands for or suggests something else by reason of association or, convention, etc; esp a visible sign of something invisible
The lion is a symbol of courage
a sign used in writing or printing to represent operations, quantities, elements, etc relations, or qualities in a particular field, e.g. chemistry or music
[Latin symbolum token, sign, symbol, from Greek symbolon, literally ‘token of identity verified by comparing its other half’, from symballein to throw together, compare, from sym- + ballein to throw]