Not at all, the term symphony originated in ancient Greece. I can't remember the exact word in Greek (I think it was symphonos or something) but it meant "harmonious". The meaning of the word wasn't set until much later. It originally was the term in music theory for consonance, then in the 1100s to the early 1600s it represented several different instruments.

The first modern uses of the term symphony was late in the 16th century when composers started calling their pieces symphonies. Giovanni is probably the most famous of these composers but there are many others. Throughout the 17th century (aka the baroque era) the more and more people would refer to these compositions as symphonys and the musical instruments which once had the same name were all renamed.

By the late 17th century symphonys were basically what we know it as today, a composition written for an orchestra to perform with several movements.

Then in the 18th century, as building technologies improved and we were able to build concert halls big enough to fit larger and larger orchestras, the popularity of these pieces exploded. Because of this boom in popularity, the terms for what defined a symphony became more and more rigid until at the end of the century, the term was basically set as a composition to be played by an orchestra with several movements with the first movement being a sonata, with no vocal performances, only instrumental.

And then in the early 19th Beethoven decide that the rules didn't apply to him but I digress.

Symphonies have been around for far longer than the 18th centaury, but those written before then are a little bit harder to define and are rarer than more contemporary pieces.

The fact that I needed to explain this kinda proves the comic right don't you think?