The most common and most likely answer to this crossword clue is the 8 letter word LIVELONG
L
I
V
E
L
O
N
G
Buddy explains!
The straight part
We know that "Complete" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case complete = livelong.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 LIVELONG mean?
LIVELONG noun- The orpine, Sedum telephium
- Total, complete, whole
- Lasting; durable.