Consider the following:

nom-sg ey-enda an island end (attributive) → the end of something, which is an island
gen-sg ey-jar-enda an island's end (partitive) → the end of an island (a point, headland)
gen-pl ey-ja-enda islands' end (unitive) → where a chain of islands end, where the open sea begins

nom-sg graf-vall a grave mound (attributive) → a burial mound, the entire mound is a grave or tomb
gen-sg graf-ar-vall a grave's tomb (partitive) → a mound or earth heap over a grave
gen-pl graf-a-vall graves' mound (unitive) → a mound where graves a dug

Would you say partitive (partial; to part) and unitive (unitary; to unite) are adequate antonyms for these particular relational functions of the genitive case?