The most common and most likely answer to this crossword clue is the 7 letter word LOG-LOG
I've seen this crossword clue in The Guardian
L
O
G
-
L
O
G
Buddy explains!

The straight part
We know that "such a plo/t" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case such a plo/t = log-log.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 LOG-LOG mean?
LOG-LOG adjective- Describing a relationship (or a graph) between logarithmic quantities (or scales)