The most common and most likely answer to this crossword clue is the 8 letter word SECONDLY
I've seen this crossword clue in The Times
S
E
C
O
N
D
L
Y
Buddy explains!

The straight part
We know that "as well" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case as well = secondly.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SECONDLY mean?
SECONDLY adverb- In the second place.