This is the 113th most frequent Icelandic word.
þúsund
The Icelandic word "þúsund" means "thousand" in English.
Here, 'þúsund' means 'a thousand', used as a quantity modifier for books.
Fjölskyldan mín fjáfesti í þúsund bókum fyrir árið.
My family invested in a thousand books for the year.
Here, 'þúsund' is used figuratively to indicate a very large number of repetitions.
Ég hljóp þúsund sinnum kringum völlinn.
I ran around the field a thousand times.
Here, 'þúsund' is used idiomatically to express gratitude in a hyperbolic manner.