The most common and most likely answer to this crossword clue is the 10 letter word INCONSTANT
I've seen this crossword clue in The Times
I
N
C
O
N
S
T
A
N
T
More clues leading to the result INCONSTANT
- Fickle bloke in fashionable Tory district at last
- Prompt to accept Conservative changing
- Conservative coming in second, being far from reliable
- Politician in a flash becoming unreliable
- In a short time a prisoner becomes disloyal
- Fickle Conservative spotted in a moment
- Often changing precise time to restrain prisoner
- Variable Jiffy bags a disadvantage
- Within a short time cheat, being fickle
- Temperamental nobhead cannot sit properly
Buddy explains!
The straight part
We know that "unreliable" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case unreliable = inconstant.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 INCONSTANT mean?
INCONSTANT adjective- Not constant; wavering.
- Unfaithful to a lover.