Undescendable is valid Scrabble Word

Is undescendable a scrabble word?
Official Scrabble Players Dictionary NO
Official Tournament and Club Word List NO
Collins Scrabble Words YES
Is undescendable valid Words with Friends?
Words with Friends NO

Definitions for UNDESCENDABLE in dictionary:

Find what other words can be done using letters: "undescendable"
https://scrabble-word.com/finder/undescendable
SCRABBLE® is a registered trademark. We do not cooperate with the owners of this trademark. All trademark rights are owned by their owners and are not relevant to the web site "scrabble-word.com". This site is intended for entertainment and training. We try to make a useful tool for all fans of SCRABBLE. "Scrabble Word" is the best method to improve your skills in the game.