Intangible means something that is incapable of being touched, it is something that isn’t exactly physically present. An intangible symbol is used to symbolise something that isn’t completely physically there, it provides another meaning. Intangible symbols can also be used to represent smells, and sounds. Example an intangible symbol, could be a ghost, its a spiritual symbol.
Another intangible symbol is a love heart, it symbolises love, which is something that is intangible.