All at once (8)
'all at once' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for suddenly that I've seen before include "Unexpectedly, abruptly" , "In an unexpected manner" , "Out of the blue" , "Happening without warning" , "Fast and unexpectedly" .)
'all at once' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for en bloc that I've seen before include "All together (French)" , "As a whole (body)" , "in wholesale fashion" , "Wholesale, as one unit" , "All together - as a whole" .)