ASSIDUOUSNESSES
Scrabble letter values: A1S1S1I1D2U1O1U1S1N1E1S1S1E1S1 = 16
Definition
ASSIDUOUSNESSES is the plural of ASSIDUOUSNESS.
noun ASSIDUOUSNESS: great and constant diligence and attention.
Synonyms of ASSIDUOUSNESS: assiduity, concentration