Untumbled is valid Scrabble Word

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

Definitions for UNTUMBLED in dictionary:

Similar words containing TUMBL without suffix ed and without prefix un

tumble10 stumble11 stumbly14 tumbled12 tumbler11 tumbles11 stumbled13 stumbler12 stumbles12 tumblers12 tumbling13 betumbled16 stumblers13 stumblier13 stumbling14 tumblebug16 tumbleset13 tumblings14 stumblebum18 stumbliest14 tumblebugs17 tumbledown18 tumblehome19 tumblerful17 tumblesets14 tumbleweed18 stumblebums19 stumblingly19 tumblehomes20 tumblerfuls18 tumblersful18 tumbleweeds19
Find what other words can be done using letters: "untumbled"
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