Large tubs used to hold or process liquids in bulk

• By extension, big tanks in brewing, winemaking, dyeing, or tanning
• Historically, a unit of liquid measure in parts of Europe

Places into a vat

• Blends wines or spirits in a vat
• Figuratively, mixes elements as if blending in a vat

Video-assisted thoracoscopic surgery, a minimally invasive chest procedure

• Uses a thoracoscope and small incisions for lung or pleural operations