Words that start with 'z' and contain 'du'

Bad news, only 2 combinations have been identified.

9 letter words

  • zardushti
  • zenaidura

How many characters are in the longest word from this list?
The longest word you could construct from words that start with 'z' and include 'du' is 'zardushti', and it consists 9 letters.

How many usable words could one put together using the specified combination?
There are 2 words.