Risibility comes via Middle French risibilité “something or someone that provokes laughter,” from Late Latin rīsibilitās (inflectional stem rīsibilitāt-) “a disposition to laugh,” a very rare noun first occurring in the works of Boethius, the most important philosopher and statesman of the late Western Roman Empire, who Dante described in his Paradiso as “the last of the Romans and first of the Scholastics.” (The Scholastics were followers of a system of theology and philosophy predominant in the Middle Ages, based chiefly upon the church fathers, Aristotle, and Aristotle's commentators). Boethius’ most important work Dē Consōlātiōne Philosophiae “The Consolation of Philosophy,” which he wrote in prison while awaiting execution, was important enough to be translated (into English) by King Alfred the Great, Geoffrey Chaucer, and Queen Elizabeth I. Perhaps the most enduring contemporary image of the Consolation is the Wheel of Fortune, now the name of a TV show. Risibility entered English in the first half of the 17th century.
The English adjective Augean comes via Latin Augēus “of Augeas” (an adjective used only of King Augeas’ stables), from the proper name Augēās (mentioned in Latin only for the dung in his stables), from Greek Augeíās. Augeíās, whose name may be related to the adjective augḗeis “bright-eyed, clear-sighted,” a derivative of augḗ “light of the sun, ray, beam,” was the king of Elis (in the western Peloponnesus); his stables, filled with 3,000 immortal cattle, had not been cleaned for over 30 years. The cattle, moreover, were not only immortal but also divinely robust and healthy and therefore produced a prodigious amount of dung. Hercules’ fifth task was to clean the dung in Augeas' stables, a task that was deliberately meant to be humiliating and impossible. Hercules cleansed the stables by diverting the river Alpheus through them. Augean entered English at the end of the 16th century.
The noun and adjective dilly, like many slang terms, has an obscure etymology. One etymology is that dilly is an alteration of delightful or delicious; the suffix -y is either the native English adjective suffix -y (as in juicy), or the originally Scottish noun suffix -y (as in granny). Dilly was originally an Americanism, first appearing in print in the early 20th century.
Samaritan as an adjective means “pertaining to Samaria or the Samaritans”; as a noun, it means “a native or inhabitant of Samaria.” Most commonly, however, Samaritan is short for Good Samaritan, after Jesus’ parable in Luke 10:30-37. Samaritan comes from the Late Latin adjective Samarītānus “Samaritan” (used as a noun in the masculine plural), from the Greek noun Samarī́tēs “a Samaritan,” a derivative of Samareía, the name of a city and region in Palestine. Greek Samareía comes from Aramaic Shamerayin, from Hebrew Shōmərôn, of uncertain meaning, but possibly from Shemer, the owner who sold Shōmərôn to Omri, king of Israel, in 1 Kings 16:24. Samaritan entered English before 1000.
The English verb stridulate, “to produce a shrill, grating sound like that of a cricket,” is an English derivative of the English noun stridulation, which comes from French stridulation. The French noun is a derivative of the New Latin verb strīdulāre “to produce a shrill, grating sound,” a derivation of the classical Latin adjective strīdulus, itself a derivation of the noun strīdor “a high-pitched sound.” Strīdere, the classical Latin equivalent of New Latin strīdulāre, is related to Greek trízein “to buzz, squeak,” and a little farther out of town, to Tocharian A trisk- “to drone” (Tocharian is the group name for two or three related Indo-European languages, now extinct, spoken in what is now Chinese Turkestan). The Latin, Greek, and Tocharian forms derive from the onomatopoeic Proto-Indo-European root (s)trei- “to buzz, hiss.” Strīdere and trízein are related to Greek strínx, stríx (stem stríng-, stríg-) “owl, night raven,” and to Latin strix (stem strig-) “an owl, bird of ill omen, evil spirit, vampire.” Either Latin strig- or Greek stríg- was the source of Vulgar Latin striga “evil spirit, witch, hag,” which becomes strega “witch” in modern Italian, as in the late Tomie DePaola’s series of wonderful children’s books “starring” Strega Nona, “Granny Witch.” Stridulate entered English in the first half of the 19th century.
You usually associate klatsch “a casual party” with coffee klatsch “a casual gathering for gossiping and drinking coffee.” Coffee klatsch is a partial rendering of German Kaffeeklatsch (in English kaffee klatsch or kaffee klatch). Coffee and Kaffee need no explanation. Klatsch is informal German for "gossip, gossiping," from the verb klatschen, of imitative origin. In German Klatsch also means "a slap, a crack (as of a bat), a clap (of the hands)." Klatsch (klatch) entered English in the 1950s.
The English adjective panivorous “bread-eating” comes from the Latin noun pānis (inflectional stem pāni-) "bread" and the Latin combining form -vorus “devouring,” a derivative of the verb vorāre “to eat up, devour” (pānivorus does not occur in Latin).
Skulduggery was originally an Americanism, a variant of Scottish sculduddery “fornication, lewd conduct, obscenity.” In American usage, skulduggery has cleaned up its act and means only “dishonorable dealings, trickery.” Neither sculduddery nor skulduggery has a reliable etymology. Sculduddery entered English in the first half of the 18th century, skullduggery in the second half.
Osmatic, “relating to the sense of smell or to animals with a keen sense of smell,” is a borrowing from French osmatique, which was coined by the 19th-century French surgeon and anthropologist Paul Broca in 1878. Osmatique derives from the Greek noun osmḗ (also odmḗ) “smell, odor, scent” and the French adjectival suffix -atique, from the same source as the English suffix -atic. Osmḗ is the classical Attic form of earlier and dialectal odmḗ, from a root od- “to smell” and is closely related to Latin odor “a smell, odor, whiff, hint.” Osmatic entered English in 1880.
The rare verb alligate comes from Latin alligātus, the past participle of alligāre “to tie, tie up, tie together,” especially in the combination or mixture of elements of different qualities or values. Alligate entered English in the 16th century.