tube definition

1. conduit consisting of a long hollow object (usually cylindrical) used to hold and conduct objects or liquids or gases
2. electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope
3. (anatomy) any hollow cylindrical body structure
4. provide with a tube or insert a tube into
5. convey in a tube
• examples: inside Paris, they used to tube mail
6. ride or float on an inflated tube
• examples: We tubed down the river on a hot summer day
7. place or enclose in a tube