Region, part of hectare, apparently (4)
I believe the answer is:
area
'region' is the definition.
(I know that region can be written as area)
'part of hectare apparently' is the wordplay.
'part of' indicates the answer is hidden within the clue.
'AREA' is hidden within 'hectare apparently'.
(Other definitions for area that I've seen before include "Region, zone" , "District; plot" , "Territory" , "Part of a building, city etc" , "Length multiplied by breadth" .)