The most common and most likely answer to this crossword clue is the 10 letter word LACKLUSTRE
I've seen this crossword clue in The Daily Telegraph
L
A
C
K
L
U
S
T
R
E
More clues leading to the result LACKLUSTRE
- Flat shortage with curious result
- Indifferent sappers have no desire to go first
- Dull king with desire to occupy large land area
- Bad luck splitting rent rates below student flat
- Not bright enough to tackle slur indirectly
- Dull? Reverse that sullen attitude during distribution of claret
- Mediocre and negligent leader getting dumped — fantastic result
- Later luck’s out — one gets dull
- Have no desire... about to become lifeless
- Dull book banned in dismal five-year period
Buddy explains!
The straight part
We know that "Mediocre" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case mediocre = lacklustre.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 LACKLUSTRE mean?
LACKLUSTRE noun- Lack of brightness or points of interest.
- A person or thing of no particular brilliance or intelligence.
- Lacking brilliance or intelligence.
- Having no shine or lustre; dull.
- Not exceptional; not worthy of special merit, attention, or interest; having no vitality.