The most common and most likely answer to this crossword clue is the 9 letter word VIDELICET
I've seen this crossword clue in Financial Times
V
I
D
E
L
I
C
E
T
More clues leading to the result VIDELICET
- Devious devil, one sort of agent briefly turning to wit
- Device lit when working, that is to say
- That is one health-food shop caught in check
- That is immoral conduct! Trump primarily lied atrociously to get in
- Evil edict is funny to wit
- Crackpot cited evil to wit
- Viz Comic’s debut featured in streaming live edit
Buddy explains!

The straight part
We know that "Viz" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case viz = videlicet.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 VIDELICET mean?
VIDELICET adverb- Namely, to wit, that is to say (used when clarifying or naming the preceding item or topic)