You must create a query that will search for your word in UserDictionary :
getContentResolver().query(UserDictionary.Words.CONTENT_URI, new String[]{UserDictionary.Words._ID, UserDictionary.Words.WORD}, //Selection UserDictionary.Words.WORD +" = ?", //Selection args new String[]{myWord}, null);
Than you can check Cursor :
if(cursor.getCount()==0){ //Word is not in dictionary }
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