Sesquipedality is the use of big words in writing (and yes, it is ironic, because it’s such a freaking long word itself). I just read the GMAU entry on it, and it’s reminded me of the daily battle I engage in as a writer, which I figured I would discuss here.
The battle goes like this: As a writer, you tend to know a lot of words. And some of those words are words that you know that other people don’t know. So what do you do? Use them, and alienate people? Or skip them, even though you know they’d make for better poetry on the page?

It turns out there are actual names for the two sides of this debate: Atticism (plain, direct) and Asiaticism (florid, bombastic). (And whether these are names to make Edward Said roll over in his grave is not today’s topic). Let’s briefly review the arguments for each side by letting them argue with each other:
Asiaticism: My gravamen here is that you are calling me pretentious just for using words you don’t know.
Atticism: Dude, stop showing off. Only nerds know what a gravamen is. And I am not a nerd. I have, like, six sports cars.
Asiaticism: I’m not showing off. The fact is that there is no word that means “gravamen” other than “gravamen.” I could talk around it, but as a writer, I care about efficiency. It’s like you gave me a leaf blower and a rake, then got pissed off that I used the leaf blower.
Atticism: But I don’t know the words you use. I don’t understand you. Is that good writing?
Asiaticism: You could look them up in a dictionary. Did a monster eat your thumbs?
Atticism: Actuall, yes.
Asiaticism: Well I was just trying to be clever.
Atticism: (under breath) Typical.
Asiaticism: You don’t need thumbs to read a dictionary, Atticus.
Atticism: But the dictionary is in the library, and I can’t open the door to get there.
Asiaticism: You have a library? In New York? How much is your rent?
Atticism: 3000 a month.
Asiaticism: How do you afford that?
Atticism: I was a thumb model.
Asiaticism: Ouch.
Atticism: Yeah. I’m looking for a new place.
Asiaticism: Anyway, you COULD look up words you don’t know.
Atticism: That’s true, but why should I have to, when you know a lot of perfectly good words you could use instead?
Asiaticism: Not perfect. Serviceable.
Atticism: Close enough. Don’t be a dick. I can’t be the first person to call you a dick for doing this.
Asiaticism: You’re not.
Okay, I think I kinda lost the plot on that one. But the point is you can marshall some solid arguments on either side of this thing. These days, the tendency is towards Atticism; I think this is partially because the conservative element in this country has fomented a distrust of academic learning, particularly academic learning that doesn’t hide itself behind plain language. Big words are inherently shameless. When you throw out a cathexis or aprotreptic, you might as well put on a t-shirt that says “I went to grad school and all I got was this t-shirt and a big vocabulary and $80,000 worth of debt.” Sesquipedality is elitist in the most literal sense.

For my own part, I’ve mostly given up the fight. I used to keep a list of words I didn’t know, for eventual use, but I haven’t added to it in years. And the vocabulary I use in my writing has gotten smaller and smaller and simpler and simpler. I’m glad I’m CAPABLE of writing like that, but I hope someday to make use of my full vocabulary with pride, much in the same way a nudist probably dreams of going into work naked. Anyway, just remember that learning new words can be fun. As long as you don’t do it sporadically. Just ask Tai and Cher, from Clueless:
SCENE XV - MAKE-OVER AT CHER’S HOUSE
“Supermodel” Jill Sobule
(Various scenes of Cher and Dionne making over Tai, then Cher and Tai working out in the lounge room)
CHER
Squeeze in.
TAI
Cher, I don’t wanna do this any more, and my buns, they don’t feel nothin’ like steel.
CHER
OK, it will get easier, I promise. Just as long as we do it every day. Not just sporadically.
TAI
How do you know if we’re doing it sporadically?
CHER
That’s another thing, Tai. We’ve got to work on your accent and vocabulary. See, sporadic means once in a while. Try using it in a sentence today.
TAI
Alright.
CHER
OK, from now on we’re alternating Cindy Crawford’s “Aerobicise” and “Buns of Steel”, and reading one non-school book a week. My first book is “Fit or Fat”.
TAI
Mine is “Men are from Mars, Women are from Venus”.
CHER
Good. Now that takes care of our minds and bodies, but we should do something good for mankind or the planet for a couple of hours.
(Josh walks in)
JOSH
Hey, brainiac.
CHER
Uh, the dreaded ex. Tai, this is Josh.
JOSH
Nice to meet ya.
CHER 
Hey! You know about this stuff. I want to do something good for humanity.
JOSH
How about sterilization?
(Tai cracks up. Cher and Josh enter the kitchen)
CHER
What do ya think?
JOSH
I’m amazed.
CHER
That I’m devoting myself so generously to someone else?
JOSH
No, that you’ve found someone ever more clueless than you are to worship you.
CHER
I am rescuing her from teenage hell. Do you know the wounds from adolescence can take years to heal?
JOSH
Yeah, and you’ve never had a mother so you’re acting out on that poor girl as if she were your Barbie doll.
CHER
Freshman psych rears it’s ugly head
JOSH
Hey, I am not taking psych.
CHER
Whatever. I am going to take that lost soul in there and make her well-dressed and popular. Her life will be better because of me. How many girls can say that about you?
(Josh and Cher walk back to the lounge where Tai is watching T.V. and singing along with the “Mentos” ad. God I hate those ads!)
JOSH
Be seein’ ya.
TAI
Yeah, I hope not sporadically
God I love Clueless.