The most common and most likely answer to this crossword clue is the 7 letter word TRACING
I've seen this crossword clue in Financial Times
T
R
A
C
I
N
G
Buddy explains!
The straight part
We know that "Outline" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case outline = tracing.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 TRACING mean?
TRACING verb- To follow the trail of.
- To follow the history of.
- To draw or sketch lightly or with care.
- To copy onto a sheet of paper superimposed over the original, by drawing over its lines.
- To copy; to imitate.
- To walk; to go; to travel.
- To walk over; to pass through; to traverse.
- To follow the execution of the program by making it to stop after every instruction, or by making it print a message after every step.
- The reproduction of an image made by copying it through translucent paper.
- A record in the form of a graph made by a device such as a seismograph.
- The process of finding something that is lost by studying evidence.
- A regular path or track; a course.