Answer: “Pattur” (exempt). This means the individual in question is legally insane (so to speak), and is therefore exempt from all mitzvos! (The word is conducive to expressing annoyance because the consonants sound like spitting).
By the way, there is a similar Teshuvah in the Tashbetz (I think), where he ridicules an ignoramus who attempts to explain the ruling of the Geonim to burn a third of the fields of a libeler, labeling him “Pattur”, as well. In subsequent teshuvos, the object himself is told of this (yes, Rechilus), assumes this means he is a woman (exempt from time-bound mitzvos) and is highly insulted, and the rabbi tries to explain he meant all he wrote in a favorable sense…
Hilarious.
I hope to find it in a few days, and update the exact source.