We don't have synonyms for greenlandish yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are greenlandic and greenlandite.
(n) :
Dated form of Greenlandic (“language of Greenland”). [The official language of Greenland, an Eskimo-Aleut language written with the Latin alphabet.]
(adj) :
Dated form of Greenlandic (“pertaining to Greenland”). [Of, from, or pertaining to Greenland, the Greenlandic people or the Greenlandic language.]
(n) :
Dated form of Greenlandic (“language of Greenland”). [The official language of Greenland, an Eskimo-Aleut language written with the Latin alphabet.]
(adj) :
Dated form of Greenlandic (“pertaining to Greenland”). [Of, from, or pertaining to Greenland, the Greenlandic people or the Greenlandic language.]