ETT

• Caspar Ett (1788–1847), German composer and organist
• English Touring Theatre

• Euler tour technique, in graph theory
• Extensional type theory, in logic

• Endotracheal tube, in respiratory medicine
• Epithelioid trophoblastic tumour, a very rare cancer
• Ergothioneine transporter, a protein and human gene (SLC22A4)
• Exercise Tolerance Test, in cardiology

• Embedded Training Teams in Afghanistan
• EBR ETT, a French armoured personnel carrier

• Elementary Teachers of Toronto, a Canadian labour union
• English Toy Terrier, a dog breed
• Etruscan language, once spoken in Italy (ISO 639-3: ett)
• European Transactions on Telecommunications, a scientific journal
• Evacuated Tube Transport

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