The most common and most likely answer to this crossword clue is the 13 letter word EMBARRASSMENT
I've seen this crossword clue in The Daily Telegraph
E
M
B
A
R
R
A
S
S
M
E
N
T
More clues leading to the result EMBARRASSMENT
- Setter put up with jiggling man breasts, right to show self-consciousness
- Humiliation as member rants drunkenly
- Mistakenly marries best man losing one’s shame
- Humiliation as member rants insanely
- Oriental doctor, by mistake arrests man in guilt
- Bans stammerer, resulting in shame
- Something that produces red pickle
Buddy explains!

The straight part
We know that "as member rants" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case as member rants = embarrassment.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 EMBARRASSMENT mean?
EMBARRASSMENT noun- A state of discomfort arising from bashfulness or consciousness of having violated a social rule; humiliation.
- A state of confusion arising from hesitation or difficulty in choosing.
- A person or thing which is the cause of humiliation to another.
- A large collection of good or valuable things, especially one that exceeds requirements.
- Impairment of function due to disease: respiratory embarrassment.
- Difficulty in financial matters; poverty.