Superfluous.
That's a word that's not always easy to work into a conversation, except under exactly the right circumstances:
Me: "Hey Doctor, I'm feeling really crappy. Body aches, headache, coughing and wheezing, the works"
Doctor: "Mr. Gecko, you have a highly contagious form of the antibiotic-resistant H1N1 flu"
Me: "Hey doc, does that mean I'm superfluous?"
You just don't get those kinds of chitchat every day!
To me, the more important thing is to be understood. That's why I never use a big word when a diminutive one will do.
And to all the trolls out there, where would you be if you weren't so pugnacious?