Pipe
To pipe is to squeeze a soft ingredient, such as frosting, onto a surface for decoration. Piping is usually done with a pastry bag.
Fun related videos

How to Pipe Éclairs and Cream Puffs

Piping Techniques - How to Pipe Choux - Cream Puffs - Éclair - Pastry Classes

Learn How to Fill a Pastry Bag and Pipe

Culinary Tips (2) Piping Buttercream

Culinary Quick Tips Piping Techniques
How to Pipe Éclairs and Cream Puffs
Source: International Culinary Center
Piping Techniques - How to Pipe Choux - Cream Puffs - Éclair - Pastry Classes
Source: Worldwide Culinary Apprentice
Learn How to Fill a Pastry Bag and Pipe
Source: The Culinary Institute of America
Culinary Tips (2) Piping Buttercream
Source: Greenville Technical College
Culinary Quick Tips Piping Techniques
Source: Greenville Technical College