þrennur

Etymology
From, from. See.

Adjective

 * 1) three (used when counting singular nouns, pluralia tantum or groupings (especially pairs) of items, or when the item counted is missing from the sentence or separated by the preposition af (“of”))
 * þrennir skór – three pairs of shoes
 * þrennir tónleikar – three concerts (tónleikar is plurale tantum)
 * Þetta má gera á þrennan hátt. – This can be done in three ways. (háttur cannot be used in its plural form in this sense)
 * Það er þrennt sem mig vantar. – There are three [things] that I need. (noun omitted)
 * Ég vil fá þrennt af öllu. – I want three of everything.