þykkustu

þykkustu is the superlative form of the Icelandic adjective "þykkur," meaning thick. In its masculine, plural, and nominative form, it translates to "the thickest." This grammatical construction indicates the highest degree of thickness among a group of masculine plural nouns. For example, if one were discussing several thick books, "þykkustu bækurnar" would refer to the thickest books among them. The word's ending changes depending on the gender, number, and case of the noun it modifies. As a superlative, it signifies a comparison where one item possesses the quality of thickness to a greater extent than all others in the relevant set. This grammatical function is common across many languages, where specific suffixes or preceding words are used to denote the highest degree of an adjective. In Icelandic, the superlative is typically formed by adding the suffix -ustu to the adjective stem, though exceptions exist.