Ior is the combined sound of io. I don’t think it has much use in modern language.
Anglo-Saxon Rune Poem (from ragweedforge.com)
Ior is a river fish and yet it always feeds on land;
it has a fair abode encompassed by water, where it lives in happiness.
Ior translates as the river fish. Most academic translations refer this to a beaver, as at the time this was written beavers (and otters) were considered very peculiar fish. It may have also referred to the otter.
In most systems, Ior is considered to metaphysically connect with Jormungand, the world serpent of Northern myth, who was one of the children of Loki and Angrboda. Some interpreters consider this a rune of happiness(because of the ending of the stanza) but others consider this the rune of boundaries, and yet also synthesis. It all has to do with the meaning of boundaries. A boundary separates one thing, from another. Yet the boundary is both things. It is In and Out, Fire and Ice, That Which is and That Which isn’t, that which can be, and that which must not be. Typically in a reading, it shows the encounter with boundaries and limits though, and only rarely is the quality of that liminal state presented.