- Water for Injection distribution loop
- water repellency
- waybill
- WFI (Water for Injection)
- WFI distribution loop
- WMS (Warehouse Management System)
- X-ray
- X-ray equipment
- xenogeneic
- xenogeneic cell therapy product
- xenogeneic cell-based medicinal product
- year
- yearly mean temperature
- yeast
- yield
- yield expected
- yield theoretical
- zero count
- zone
- zone administration