\begin{definition}[Definition:Imperial/Volume/Barrel]
The '''barrel''' is an imperial unit of volume.
{{begin-eqn}}
{{eqn | o = 
      | r = 1
      | c = '''barrel'''
}}
{{eqn | r = 2
      | c = kilderkins
}}
{{eqn | r = 0 \cdotp 14547 \, 488
      | c = cubic metres
}}
{{eqn | r = 145 \cdotp 47488
      | c = litres
}}
{{end-eqn}}
\end{definition}