21-letter words containing o, a, n, s
- 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
- xeroderma pigmentosum — a rare inherited disease characterized by sensitivity to ultraviolet light, exposure resulting in lesions and tumors of the skin and eyes.
- 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