The definition is anything but...

I used the word 'pithy' today on a conference call. At first, everyone thought I said 'pissy,' which given the context was wholly inappropriate but also quite amusing. After we cleared that up, someone googled the definition: "[n. PIH-thee] Pithy, when used accurately, describes speech or writing that is short, direct, and memorable."

I'm not a linquist by any means, but isn't the meaning of a word always predicated on it being used accurately?

mw