\begin{definition}[Definition:Avoirdupois/Quarter]
The '''quarter''' is an avoirdupois unit of mass.
{{begin-eqn}}
{{eqn | o = 
      | r = 1
      | c = '''quarter'''
}}
{{eqn | r = 2
      | c = stone
}}
{{eqn | r = 28
      | c = pounds avoirdupois
}}
{{eqn | o = \approx
      | r = 12 \cdotp 7
      | c = kilograms
}}
{{end-eqn}}
\end{definition}