Interjection

1. The cry of a monkey.
   • 1995, Terry Pratchett, Soul Music

     He tapped the Librarian on the shoulder. "Excuse me —" "Ook?" "Those guys just called you a monkey," said Glod.

   • 2004, Robert Arellano, Don Dimaio of La Plata

     The irate ape cries, "Ook ook! Ai ai at!" He springs off the edge of the stone basin, clawing Cantare across the face and bursting through the door.

Adverb

1. also, too, moreover

   Dat kan ik ook. – I can do that too.

2. (in negative sentences) either

   Ik kan dat ook niet. – I can't do that either.

3. -ever

   wie dan ook – whoever

   waar ook – wherever

4. particle for emphasis

   Het heeft ook heel lang geduurd. – It did take very long.