You can make 10 words from koro according to the Scrabble US and Canada dictionary.
All 4 letters words made out of koro
koro okro kroo rkoo orko roko koor okor koor okor ookr ookr kroo rkoo koro okro roko orko orok rook oork oork rook orok
Note: these 'words' (valid or invalid) are all the permutations of the word koro. These words are obtained by scrambling the letters in koro.
Definitions and meaning of koro
koro
Etymology
Possibly from Makasargarringkoro' (lit. koro illness, "shrinking of the toilet", Matthes 1859), Buginese, or Malay. See "Koro § Etymology and geographical background" at Wikipedia for a full discussion.
Noun
koro (uncountable)
(psychology) A delusional syndrome found in Malay and southern Chinese populations, characterized by a belief that the subject's penis will retract into the abdomen and cause death.
References
Mathes B. F. (1859). Makassaarsch-Hollandsch Woordenboek. Amsterdam: Het Nederlandsch Bijbelgenootschap te Amsterdam, p. 43 ("inkrimping van het gemak").