I recently listened to an episode of Our Life in Christ -- a podcast at Ancient Faith Radio -- which discussed the sacraments of the Orthodox Church and referenced the book I'm currently reading on the same subject, For The Life of The World by Alexander Schmemmann.
The Greek word translated as 'symbol' is Σύμβολο (sýmvolo), and it meant 'to throw together' or 'the joining of two things into one.' One supposes that 'symbol' is a cognate of 'symbiosis', but obviously the meaning of these two words are currently different from one another. It seems that 'symbiosis' retained a meaning closer to its etymological origin, while 'symbol' has drifted. Today we understand 'symbol' to roughly mean 'one thing that stands for or represents or images forth another thing.' Not two things coming together in a living, interacting unity, a la symbiosis. The latter understanding seems to describe the nature of a high sacramentology -- the bread and wine becoming the body of Christ, thereby transforming the Church into the actual body of Christ; baptism as an actual death to our old self and actual resurrection to new life joined to Christ and his Church etc. -- more accurately than it does a 'symbolic' (in today's meaning) representation of a decision for Christ, or a mental recollection of the cross.
And it's not as if the Church Fathers didn't have a Greek word at their disposal that could express this idea of two different things beside each other, one standing for the other. They had that word and it was παραβολή (paràbola), which defined exactly that concept. 'Paràbola' meant (roughly) 'two things alongside one another' and is the word from which we derive -- among other words -- the English word 'parable'. A parable being one story that stands for another story or reality, while remaining separate. This is closer to what we mean today when we use the words 'symbol' and 'symbolism', but the Fathers didn't use this word because it wasn't what they meant.
That is the argument that is made in the podcast, at any rate, and one that seemed persuasive to me.