| W | Tungsten |
| W3C | World Wide Web Consortium |
| WAN | Wide Area Network |
| WAP | Wireless Application Protocol |
| WAV | Waveform Audio |
| W-BIT | Wait-bit |
| W/B | Wire Bonding |
| WB | Weak Base |
| WBC | White Blood Cell |
| WBEM | Web-Based Enterprise Management |
| WBSEM | Wire Bonder Specific Equipment Model |
| WBS | Work Breakdown Structure |
| WCDMA | Wideband Code-Division Multiple-Access |
| WDM | Wavelength Division Multiplexing |
| WDS | Wavelength-Dispersive (X-ray) Spectroscopy (aka WDX) |
| WDX | Wavelength-Dispersive X-ray Spectroscopy (aka WDS) |
| WDXA | Wavelength-dispersive X-ray analysis |
| WeatherML | Weather Mark-up Language |
| WebDAV | Web Distributed Authoring and Versioning |
| WEC | Wafer environment control |
| WEDE | Wireless Enterprise Delivery Environment |
| WEP | Wired Equivalent Privacy |
| WFT | Wafer fabrication template |
| WIB | Within-batch |
| WIP | Work in process; work in progress |
| WIS | Water induced shift |
| WITNESS | Wireless Integrated Terminal & Network Experimentation & Services |
| WIW | Within wafer |
| WIWNU | Within wafer nonuniformity |
| WLAN | Wireless Local Area Network |
| WLBI | Wafer-level burn-in |
| WLT | Wafer-level test |
| WMF | Windows Metafile image format |
| WMI | Windows Management Instrumentation |
| WML | Wireless Markup Language |
| WMT | Windows Media Technology |
| WNP | Waste Neutralization Plant |
| WORM | Write Once Read Many |
| WPC | Wafer Process Chamber |
| WPG | WordPerfect Bitmap image format |
| WPH | Wafers per hour |
| WSDL | Web Services Description Language |
| WSI | Wafer-scale integration |
| WTC | Wafer transfer chamber |
| WTW | Wafer-to wafer |
| WTWNU | Wafer-to wafer nonuniformity |
| WVR | Water Vapor Regained |
| WWW | World Wide Web |
| WYSIWYG | What You See Is What You Get |
| X | Inductive reactance |
| XANES | X-ray Absorption Near-Edge Structure |
| XAS | X-ray Absorption Spectroscopy |
| XBRL | eXtensive Business Research Language |
| Xe | Xenon |
| xHTML | eXtensible Hypertext Mark-up Language |
| XIP | eXecute In Place |
| XLS | eXcimer Laser System; eXtended Light Scatterer |
| XMCL | eXtensible Media Common Language |
| XML | eXtensible Markup Language |
| XML-RPC | XML Remote Procedure Calls |
| XMP | X-ray Micro-Probe; eXtensible Metadata Platform |
| XOR | Logic term - XOR |
| XPRL | eXtensive Public Relations Language |
| XPS | X-ray Photoelectron Spectroscopy |
| X-ray | Röntgen beam technology |
| XR | X-ray Reflectivity |
| XRD | X-ray Diffraction |
| XRF | X-ray fluorescence spectrometry |
| XRML | eXtensible Rights Markup Language |
| XSL | eXtensible Style sheet Language |
| XSLT | eXtensible Style sheet Language Transformations |
| XTEM | Cross sectional Transmission Electron Microscopy |
| Y | Yttrium |
| Y2K | Year 2000 (chip program bug) |
| YAG | Yttrium aluminum garnet |
| Yb | Ytterbium |
| yocto | 1.00E-24 (1/1,000,000,000,000,000,000,000,000; symbolized by the prefix y) |
| yotta | 1.00E+24 (1,000,000,000,000,000,000,000,000/1; symbolized by the prefix Y) |
| ZAF | Z-axis Adhesive Film |
| ZAP | Zone Axis Pattern |
| zepto | 1.00E-21 (1/1,000,000,000,000,000,000,000; symbolized by the prefix z) |
| zetta | 1.00E+21 (1,000,000,000,000,000,000,000; symbolized by the prefix Z) |
| ZFC | Zero Field Cooling |
| ZIF | Zero Insertion Force |
| ZIP | Zigzag Inline Package; Archived file format |
| Zn | Zinc |
| ZnS | Zinc Sulphide |
| ZnSe | Zinc Selenide |
| ZnTe | Zinc Telluride |
| ZOLZ | Zero-Order Laue Zone |
| ZPL | Zero Phonon Line |
| Zr | Zirconium |
