The most common and most likely answer to this crossword clue is the 9 letter word TECHNICAL
I've seen this crossword clue in The Times
T
E
C
H
N
I
C
A
L
More clues leading to the result TECHNICAL
- Fixing chain etc on wheel finally is complex
- Specialist caught occupying chalet in novel
- Scientific investigator left with fragments of china
- Specialist element said to be backing police investigator
- Scientific reappraisal of clan ethic
- Specialist used it with chancel refurbishment
- Specialist to lecture without a bit of money, say
- Specialist from California supporting detective with hazardous nuclear investigation initially
- Catch with line at sea, as per strict rules
- Expert starts to turn left, negotiating awkward chicane
Buddy explains!
The straight part
We know that "complex" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case complex = technical.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 TECHNICAL mean?
TECHNICAL noun- A pickup truck with a gun mounted on it.
- A technical foul: a violation of sportsmanlike conduct, not involving physical contact.
- A special move in certain fighting games that cancels out the effect of an opponent's attack.
- Short for technical school.
- Short for technical course.
- Short for technical examination.
- Of or pertaining to the useful or mechanic arts, or to any academic, legal, science, engineering, business, or the like terminology with specific and precise meaning or (frequently, as a degree of distinction) shades of meaning; specially appropriate to any art, science or engineering field, or business
- (of a person) Technically-minded; adept with science and technology.
- Relating to, or requiring, technique.
- Requiring advanced techniques for successful completion.
- (securities and other markets) Relating to the internal mechanics of a market rather than more basic factors.
- In the strictest sense, but not practically or meaningfully.