21-letter words containing e, n, t, o, i
- white-crowned sparrow — a North American sparrow, Zonotrichia leucophrys, having black and white stripes on the head.
- william the conqueror — ("the Conqueror") 1027–87, duke of Normandy 1035–87; king of England 1066–87 (son of Robert I, duke of Normandy).
- wilson's storm petrel — a small petrel, Oceanites oceanicus, that breeds in the Southern Hemisphere but ranges into the North Atlantic and Pacific oceans.
- with one's bare hands — If someone does something with their bare hands, they do it without using any weapons or tools.
- with sb's compliments — If you say that you are giving someone something with your compliments, you are saying in a polite and fairly formal way that you are giving it to them, especially as a gift or a favour.
- with the exception of — except for, save
- word association test — a technique for determining a subject's associative pattern by providing a verbal stimulus to which a verbal response is required.
- word-association test — a psychological test in which the person being tested responds to a given word with the first word (or the first word in a specified category, such as an antonym) brought to mind
- workers' compensation — a government-sponsored insurance system, funded by contributions from employers, for compensating employees for injury or occupational disease suffered in connection with their employment
- worth someone's while — worth someone's time, consideration, etc.; profitable in some way
- xeroderma pigmentosum — a rare inherited disease characterized by sensitivity to ultraviolet light, exposure resulting in lesions and tumors of the skin and eyes.
- xfree86 project, inc. — (operating system, graphics) A non-profit organisation that produces XFree86, a freely redistributable implementation of the X Window System that runs on Unix and Unix-like operating systems and OS/2. The XFree86 Project has traditionally focused on Intel x86 based platforms (hence the "86"), but the current release supports other platforms.
- xilinx netlist format — (language, electronics) (XNF) A Hardware Description Language for electronic circuit design, developed by Xilinx, Inc..
- youth training scheme — (formerly, in Britain) a scheme, run by the Training Agency, to provide vocational training for unemployed 16–17-year-olds