21-letter words containing y, e, i, s
- ventriloquist's dummy — a puppet which is operated by a ventriloquist and made to appear to talk
- virtual memory system — (operating system) (VMS) DEC's proprietary operating system originally produced for its VAX minicomputer. VMS V1 was released in August 1978. VMS was renamed "OpenVMS" around version 5.5. The first version of VMS on DEC Alpha was known as OpenVMS for AXP V1.0, and the correct way to refer to the operating system now is OpenVMS for VAX or OpenVMS for Alpha. The renaming also signified the fact that the X/Open consortium had certified OpenVMS as having a high support for POSIX standards. VMS is one of the most secure operating systems on the market (making it popular in financial institutions). It currently (October 1997) has the best clustering capability (both number and distance) and is very scalable with binaries portable from small desktop workstations up to huge mainframes. Many Unix fans generously concede that VMS would probably be the hacker's favourite commercial OS if Unix didn't exist; though true, this makes VMS fans furious.
- voice-stress analyzer — a machine purported to detect stress in a human voice and to ascertain a person's truthfulness.
- weinberg-salam theory — electroweak theory.
- west university place — a city in SE Texas.
- william of malmesbury — William of, William of Malmesbury.
- yellow lady's-slipper — a showy orchid, Cypripedium calceolus, of eastern North America, having purple-tinged yellow flowers with an inflated lip petal.
- yellow-fever mosquito — a mosquito, Aedes aegypti, that transmits yellow fever and dengue.
- youth training scheme — (formerly, in Britain) a scheme, run by the Training Agency, to provide vocational training for unemployed 16–17-year-olds