We don't have synonyms for hectad yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are heptad, ectad and hecta.
(n) :
(biology, cartography) A unit of land area, ten by ten (that is, a hundred) square kilometres, often used for assessing how widely distributed particular animals or plants are.
(n) :
(biology, cartography) A unit of land area, ten by ten (that is, a hundred) square kilometres, often used for assessing how widely distributed particular animals or plants are.