\begin{definition}[Definition:Historic Measures/Length/Leuca]
The '''leuca''' is a unit of length.
{{begin-eqn}}
{{eqn | o = 
      | r = 1
      | c = '''leuca'''
}}
{{eqn | r = 1500
      | c = paces
}}
{{eqn | r = 7500
      | c = feet
}}
{{eqn | r = 90 \, 000
      | c = inches
}}
{{end-eqn}}
\end{definition}