vindictive
The ten-letter word for letters that are not vowels is consonants.
recreation
CONCOCTION
carnations
The word reversible itself is ten letters.Another possibility is palindrome.
A ten letter word that means equal to is equivalent.
appreciate
I think it is exhibition
downstream
The ten-letter word for letters that are not vowels is consonants.
recreation
introspect
commission
co-operates
everywhere
bridegroom
Mysterious