STOP THE PRESSES! HOLD THE PHONE! CALLING ALL CARS

Finally, the mystery of all mysteries has been solved (with little-to-no-help from the internets, I might add).

AJ was happy to point me in the right direction after learning of my plight:

Arliss Coates: Why did you shoot Rosemary?
Travis Coates: She was sick.
Arliss Coates: Well, you were sick. How come we didn’t shoot you?
AJ Scrotes: i just saw picayune!
AJ Scrotes: on something awful
AJ Scrotes: in a sentence
AJ Scrotes: here’s a fragment
AJ Scrotes: “navigating vast realms and completing picayune tasks”
Travis Coates: That was different.

Er.. sorry, I was recalling events while thinking about Old Yeller. You know how that goes. Here’s the SA link, sent to me from the heavens, to set me on the correct path.

So, basically, this the correct spelling of “picayune.” Answers.com filled in the rest:

Dictionary: pic·a·yune (pĭk’ə-yūn’)

adj.

1. Of little value or importance; paltry. See synonims at trivial.
2. Petty; mean.

n.

1. A Spanish-American half-real piece formerly used in parts of the southern United States.
2. A five-cent piece.
3. Something of very little value; a trifle: not worth a picayune.

[Louisiana French picaillon, small coin, from French, from Provençal picaioun, from picaio, money, perhaps from Old Provençal piquar, to jingle, clink, from Vulgar Latin *piccāre, to pierce. See pique.]
picayunish pic’a·yun’ish adj.

In fact, I’ve heard the term picayune before (and of Picayune, MS!), though never the adjective picayunish. I can see how either the noun or adjective could easily become mispronounced as picky-uni … Although, the meaning associated with the word, as I have come to know it from context — overly choosy or picky — isn’t really the true meaning.

I have to assume, those that have misheard or mispronounced this word, assuming it’s root was picky, invented a new almost-not-exactly-related meaning. Imagine a phrase like “being choosy about picayune details” restructured as “being picky-uni about details.” Weird, but plausible.

I can now sleep soundly once again. Thanks AJ.