18-letter words containing a, n, d, o, u, i
- thioarsenious acid — any of a group of hypothetical acids, H3AsS3, HAsS2, and H4As2S5, known only in the forms of their salts
- to find fault with — If you find fault with something or someone, you look for mistakes and complain about them.
- to speak your mind — If you speak your mind, you say firmly and honestly what you think about a situation, even if this may offend or upset people.
- tristan und isolde — a music drama (composed, 1857–59; première, 1865) by Richard Wagner.
- ultrasonic welding — the use of high-energy vibration of ultrasonic frequency to produce a weld between two components which are held in close contact
- under the aegis of — guided or protected by
- under-compensation — to compensate or pay less than is fair, customary, or expected.
- under-depreciation — decrease in value due to wear and tear, decay, decline in price, etc.
- under-registration — the act of registering.
- united nations day — the anniversary of the United Nations on October 24, marking its founding in 1945.
- urban homesteading — homesteading (def 2).
- vanadium pentoxide — a yellow to red crystalline compound, V 2 O 5 , slightly soluble in water, used as a catalyst for organic reactions, in glass to absorb ultraviolet radiation, and as a photographic developer.
- video surveillance — a system of monitoring activity in an area or building using a television system in which signals are transmitted from a television camera to the receivers by cables or telephone links forming a closed circuit
- widemouth blindcat — any of several catfishes, as Satan eurystomus (widemouth blindcat) of Texas, that inhabit underground streams and have undeveloped eyes and unpigmented skin.
- wrongful dismissal — the act of making someone redundant for reasons which are illegal or unjust
- xenon hexafluoride — a colorless, crystalline compound, XeF 6 , that melts at 50°C to a yellow liquid, and boils at 75°C.