Unopposing is valid Scrabble Word

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

Definitions for UNOPPOSING in dictionary:

Similar words containing OPPOS without suffix ing and without prefix un

oppos9 oppose10 opposed12 opposer11 opposes11 opposers12 opposing13 opposite12 reoppose12 opposable15 opposably18 opposites13 reopposed14 reopposes13 unopposed14 opposeless14 opposingly18 oppositely17 opposition14 oppositive17 reopposing15 oppositions15 opposability21 oppositeness16 oppositional16 oppositionist17 opposabilities20 oppositenesses18 oppositionists18 oppositionless18
Find what other words can be done using letters: "unopposing"
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