The most common and most likely answer to this crossword clue is the 8 letter word COMPLETE
I've seen this crossword clue in The Daily Telegraph
C
O
M
P
L
E
T
E
More clues leading to the result COMPLETE
- Struggle across line to finish
- Perfect finish
- Engage in competition without money to finish
- Take part, bagging large total
- Rival crosses line to finish
- Struggle to accept Labour’s leader is perfect
- Take part divided by fifty to produce whole
- Absolute ‘catch’ allowed sweetheart to embrace male
- Enter about fifty in total
- Full make up?
Buddy explains!

The straight part
We know that "perfect" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case perfect = complete.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 COMPLETE mean?
COMPLETE noun- A completed survey.
- To finish; to make done; to reach the end.
- To make whole or entire.
- To call from the small blind in an unraised pot.
- With all parts included; with nothing missing; full.
- Finished; ended; concluded; completed.
- Generic intensifier.
- (of a metric space) In which every Cauchy sequence converges to a point within the space.
- (of a lattice) In which every set with a lower bound has a greatest lower bound.
- (of a category) In which all small limits exist.
- (of a proof system of a formal system with respect to a given semantics) In which every semantically valid well-formed formula is provable.
- (of a problem) That is in a given complexity class and is such that every other problem in the class can be reduced to it (usually in polynomial time or logarithmic space).