hvötum
Hvítum is a form of the Icelandic adjective hvítur, which means "white." In Icelandic, adjectives agree with the nouns they modify for gender, number, and case, and hvítum represents one of the inflected endings that can occur in this system.
In practical usage, hvítum appears as an inflected variant used with plural nouns in certain grammatical cases,
Etymology traces hvítur to the Old Norse word for white, with hvítum sharing the same root as
hvítum is therefore best understood as a grammatical variant rather than as a standalone lexical item.
See also: Icelandic grammar, Icelandic adjectives, color terms in Icelandic.