Teachers reinterpreted units of measurement (8)
I believe the answer is:
hectares
'units of measurement' is the definition.
(hectare is a unit for measuring land area)
'teachers reinterpreted' is the wordplay.
'reinterpreted' is an anagram indicator.
'teachers' with letters rearranged gives 'HECTARES'.
(Other definitions for hectares that I've seen before include "areas of land" , "Square measures" , "Metric units of land measurement" , "Metric measures for land" , "Metric measures of areas" .)