Shard

A portmanteau of the verbs "shit" and "fart," which describes the instance of accidentally shitting one's pants based on the assumption of farting prior to release. A bit of technical information: Despite one's intuition that the un-inflected form of the verb would be "shart," (borrowing the onset from "shit" and the rhyme of "fart") It's phonological realization, "shard," implies that the word entered the lexicon as "sharted." Much in the same way the words "writer" and "rider" can not be distinguished from one another in speech with out a rich enough context (because they sound the same), "sharded" and "sharted" will also sound identical due to flapping. Hence, speakers of English chose "shard" as opposed to "shart" by means of back-formation. Selection of the phoneme /d/ over /t/ can likely be attributed to the feature {+voice} of the flapped consonant.