\begin{definition}[Definition:Imperial/Volume/Fluid Ounce]
The '''fluid ounce''' is an imperial unit of volume.
{{begin-eqn}}
{{eqn | o = 
      | r = 1
      | c = '''fluid ounce'''
}}
{{eqn | r = \dfrac 1 {20}
      | c = pint
}}
{{eqn | r = 28 \cdotp 41306 \, 25
      | c = millilitres
}}
{{end-eqn}}
\end{definition}