The most common and most likely answer to this crossword clue is the 8 letter word MEDIOCRE
I've seen this crossword clue in Financial Times
M
E
D
I
O
C
R
E
More clues leading to the result MEDIOCRE
- Average doctor about to hold round
- Ordinary dormice mistreated by English
- Average doctor has nothing to carry about
- Not very good doctor about to introduce oxygen
- Julius? Old, cold, boring, disastrous, second-rate
- I’d come upset about something commonplace
- Ordinary doctor eating nothing’s regularly true
- Simple holding company I had set up, undistinguished
- Doctor about to accept nothing average
- 26 only about part of bishopric
Buddy explains!

The straight part
We know that "something commonplace" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case something commonplace = mediocre.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 MEDIOCRE mean?
MEDIOCRE noun- A person of minor significance, accomplishment or acclaim; a common and undistinguished person.
- A member of a socioeconomic class between the upper ranks of society and the agricultural workers.
- Having no peculiar or outstanding features; not extraordinary, special, exceptional, or great; of medium quality, almost always with a negative connotation.