21-letter words containing l, d, o
- well-ordering theorem — the theorem of set theory that every set can be made a well-ordered set.
- wet collodion process — a photographic process, in common use in the mid-19th century, employing a glass photographic plate coated with iodized collodion and dipped in a silver nitrate solution immediately before use.
- what the future holds — If you wonder what the future holds, you wonder what will happen in the future.
- wholesale price index — an indicator of price changes in the wholesale market
- wildlife photographer — someone that specializes in taking photographs of wild animals, especially in their natural habitats, and plants
- yellow lady's-slipper — a showy orchid, Cypripedium calceolus, of eastern North America, having purple-tinged yellow flowers with an inflated lip petal.
- yellow mercuric oxide — a slightly crystalline, water-soluble, poisonous compound, HgO, occurring as a coarse, orange-red powder (red mercuric oxide) or as a fine, orange-yellow powder (yellow mercuric oxide) used chiefly as a pigment in paints and as an antiseptic in pharmaceuticals.
- yellow-flowered gourd — the hard-shelled fruit of any of various plants, especially those of Lagenaria siceraria (white-flowered gourd or bottle gourd) whose dried shell is used for bowls and other utensils, and Cucurbita pepo (yellow-flowered gourd) used ornamentally. Compare gourd family.
- yellow-rumped warbler — a common North American wood warbler, Dendroica coronata, having yellow spots on the rump, crown, and sides, including a white-throated eastern subspecies (myrtle warbler) and a yellow-throated western subspecies (Audubon's warbler)
- yellow-throated vireo — an olive-green vireo, Vireo flavifrons, of eastern North America, having a bright yellow throat and breast.
- zedillo ponce de leon — Ernesto, born 1951, president of Mexico 1994–2000.