Completely Crossword Clue

 Here are some possible answers for the crossword clue "completely":

ALTOGETHER (10 letters)

 ENTIRELY (8 letters)

 UTTERLY (7 letters)

 WHOLLY (6 letters)

 TOTALLY (7 letters)

These words all mean "in every way" or "to the fullest extent". They are all good fits for a crossword clue, as they are relatively short and easy to remember.