Home › Words › I › isogrivisogriv/ˈaɪsoʊɡɹɪv/isogriv means A line on a map or chart which joins points of equal grivation, that is, equal angle between grid north and magnetic north.isogriv is pronounced /ˈaɪsoʊɡɹɪv/.EtymologyFrom iso- + clipping of grivation.nounA line on a map or chart which joins points of equal grivation, that is, equal angle between grid north and magnetic north.Definitions & examples from Wiktionary (CC BY-SA 3.0).