\startbuffer[definitions]

\setupunittext
  [whatever]
  [meter=retem,
   second=dnoces]

\setupprefixtext
  [whatever]
  [kilo=olik]

\setupoperatortext
  [whatever]
  [solidus={ rep }]
\stopbuffer

\startbuffer[sample]
\startlines
\lunit{10 km/s}
\lunit{10 Kilo Meter/s}
\lunit{10 kilo Meter/s}
\lunit{10 Kilo m/s}
\lunit{10 k Meter/s}
\stoplines
\stopbuffer

\setuplayout[header=0pt] \setuplayout[middle]

\starttext

\typebuffer[definitions] \getbuffer[definitions]

\startbuffer
\typebuffer[sample]

\defineunit[lunit]                    \getbuffer[sample]
\defineunit[lunit][language=whatever] \getbuffer[sample]
\stopbuffer

\typebuffer \getbuffer

\stoptext
