Online Etymology Dictionary

saddle (n.): O.E. sadol "seat for a rider," from P.Gmc. *sathulaz (cf. O.N. söðull, O.Fris. sadel, Du. zadel, zaal, Ger. Sattel), from PIE *sed- "to sit" (cf. L. sedere "to sit," O.C.S. sedlo "saddle;" see sedentary). Fig. phrase in the saddle "in an active position of management" is attested from 1660. The verb is from O.E. sadolian; the meaning "to load with a burden" is first recorded 1693. Saddleback is from 1545. Saddlebag is from 1774.
settle (n.): "long bench," O.E. setl "a seat, position, abode," related to sittan "to sit," from P.Gmc. *setla- (cf. M.L.G., M.Du. setel, Du. zetel, Ger. Sessel, Goth. sitls), from PIE *sedla- (cf. L. sella "seat, chair," O.C.S. sedlo "saddle," O.E. sadol "saddle"), from base *sed- "to sit" (see sedentary).
side-saddle (n.): 1493, from side (adj.) + saddle (n.).
clitellum: "raised band around an earthworm," 1839, from Mod.L., from L. clitellae "a pack-saddle."
pommel: early 14c., from O.Fr. pomel (12c.), "rounded knob," dim. of pom "hilt of a sword," from L.L. pomellum, dim. of L. pomum "apple," the connecting notion being "roundness." Sense of "front peak of a saddle" first recorded mid-15c. In M.E. poetry it also sometimes meant a woman's breast.
daylight: c.1300, from day + light (n.); its figurative sense of "clearly visible open space between two things" (1820) has been used in references to boats in a race, U.S. football running backs avoiding opposing tackles, a rider and a saddle, and the rim of a glass and the surface of the liquor. The daylights that you beat out of someone were originally slang for "the eyes" (1752), extended figuratively to the vital senses.
batman: "officer's servant," originally military title for "man in charge of a bat-horse and its load," 1755, from bat "pack-saddle" (late 14c.), from O.Fr. bast (Mod.Fr. bât), from L.L. bastum (see baton). Hence also batwoman (1941).
cinch: 1859, Amer.Eng., "saddle-girth," from Sp. cincha "girdle," from L. cingulum "a girdle," from cingere "to surround, encircle," from PIE base *kenk- "to gird, encircle." Sense of "an easy thing" is 1898, via notion of "a sure hold" (1888). The verb is first recorded 1866.
caparison: 1598, "cloth spread over a saddle," also "personal dress and ornaments," from Fr. caparasson (Mod.Fr. caparaçon, from Sp. caparazon, from augmentative of M.L. caparo, the name of a type of cape worn by women, lit. "chaperon" (see chaperon). Pp. adj. caparisoned is attested from 1600, from a verb caparison (1594).
panel: c.1300, from O.Fr. panel "saddle cushion, piece of cloth," from V.L. *pannellus, dim. of L. pannus "piece of cloth" (see pane). Anglo-Fr. sense of "piece of parchment (cloth) listing jurors" led by late 14c. to meaning "jury." General sense of "persons called on to advise, judge, discuss," etc. is from 1570s. Sense of "distinct part of surface of a wall, door, etc." is first recorded c.1600.
palfrey: 1148, "saddle horse for ordinary riding (opposed to a war horse), small horse for ladies," from O.Fr. palefrei (11c.), from M.L. palafredus, alt. by dissimilation from L.L. paraveredus "post horse for outlying districts" (6c.), originally "extra horse," from Gk. para "beside, secondary" + L. veredus "post horse; light, fast horse used by couriers," from Gaul. *voredos (cf. Welsh gorwydd "horse," O.Ir. riadaim "I ride"). The L. word passed to O.H.G. as pfarifrid, where in modern Ger. it has become the usual word for "horse" (pferd).
-able: suffix expressing ability, capacity, fitness, from Fr., from L. -ibilis, -abilis, forming adjectives from verbs, from PIE *-tro-, a suffix used to form nouns of instrument. In L., infinitives in -are took -abilis, others -ibilis; in Eng., -able is used for native words, -ible for words of obvious L. origin. The Latin suffix is not etymologically connected with able, but it long has been popularly associated with it, and this has contributed to its survival as a living suffix. It is related to the second syllable of rudder and saddle.
pack (n.): "bundle," early 13c., probably from a Low Ger. word (cf. M.Du. pac, pack "bundle," M.L.G. pak, M.Flem. pac, attested from 1199), originally a term of wool traders in Flanders; or possibly from O.N. pakki, all of unknown origin. Italian pacco is a Du. loan word. Meaning "set of persons" (usually of a low character" is c.1300, older than sense of "group of hunting animals" (early 15c.). Extended to collective sets of playing cards (1590s), floating ice (1791), cigarettes (1924), and submarines (1943). Meaning "knapsack on a frame" is attested from 1916. Pack-horse is from late 15c.; packsaddle "saddle for supporting packs on the back of a mount" is from late 14c. (pakke sadil). Pack of lies first attested 1763.
pig: probably from O.E. *picg, found in compounds, ultimate origin unknown. Originally "young pig" (the word for adults was swine). Another O.E. word for "pig" was fearh, related to furh "furrow," from PIE *perk- "dig, furrow" (cf. L. porc-us "pig," see pork). "This reflects a widespread IE tendency to name animals from typical attributes or activities" [Lass]. Synonyms grunter, porker are from sailors' and fishermen's euphemistic avoidance of uttering the word pig at sea, a superstition perhaps based on the fate of the Gadarene swine, who drowned. The meaning "oblong piece of metal" is first attested 1589, on the notion of "large mass." The derogatory slang meaning "police officer" has been in underworld slang since at least 1811; pig out "eat like a pig" is 1979; pig-headed is 1620; pigskin as slang for "football" is from 1894, though as word for saddle leather it is from 1855. Pig Latin first recorded 1937. Pigsty is from 1591; fig. use for "miserable, dirty hovel" is attested from 1820.