"a toad, a frog," late 14c., paddok (late 12c. as a surname), probably a diminutive of pad "toad," from Old Norse padda; from Proto-Germanic *pado- "toad" (source also of Swedish padda, Danish padde, Old Frisian and Middle Dutch padde "frog, toad," also Dutch schildpad "tortoise"), of unknown origin and with no certain cognates outside Germanic. Paddock-stool was an old name for a toadstool (mid-15c.). Pad in the straw was a 16c.-17c. expression meaning "something wrong, hidden danger."
"removable lock with a pivoted bow or hasp," late 15c., pad-lok, from lock (n.1), but the first element is of obscure origin; perhaps originally, as some sources suggest, "a lock for a pannier."
"padding in the upper back part of a skirt," 1788, of uncertain origin, perhaps from German Buschel "bunch, pad," or it might be a special use of bustle (n.1) with reference to "rustling motion."
BUSTLE. A pad stuffed with cotton, feathers, bran, &c., worn by ladies for the double purpose of giving a greater rotundity or prominence to the hips, and setting off the smallness of the waist. [Bartlett, "Dictionary of Americanisms," 1848]
Century Dictionary (1895) notes that, in addition to "improving the figure" it causes the folds of the skirt to hang gracefully and prevents the skirt from interfering with the feet in walking.
kind of light, simple saddle, especially for women, c. 1500, of Celtic origin (compare Irish pillin, Gaelic pillin), ultimately from Latin pellis "skin, pelt" (from PIE root *pel- (3) "skin, hide"). Later also "adjustable pad or cushion behind a saddle as a seat for a second person, usually a woman."
"tail, something hanging down," variant of queue (n.), ultimately from Latin cauda "tail." Meaning "long roll or plait of a wig or hair worn hanging down, a pigtail," is from 1731. Meaning "straight, tapering rod with a small soft pad, used in billiards," is by 1749. Hence cue-ball, the ball struck by the cue, recorded by 1881.