The most common and most likely answer to this crossword clue is the 8 letter word LANGUISH
I've seen this crossword clue in The Daily Telegraph
L
A
N
G
U
I
S
H
More clues leading to the result LANGUISH
- Latin maybe is hard — time to go off and flop?
- Sink a gin, drunk with lush
- Flag and sail hung incorrectly
- Suffer deprivation in Libya’s capital, and mental torture
- Wilt thou finally put in indication about husband?
- Flag hung — sail at sea
- Number suffering become depressed
- Droop when left with misery
- Suffering under Labour leader’s decline
- Left with pain, weaken
Buddy explains!

The straight part
We know that "become depressed" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case become depressed = languish.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 LANGUISH mean?
LANGUISH verb- To lose strength and become weak; to be in a state of weakness or sickness.
- To pine away in longing for something; to have low spirits, especially from lovesickness.
- To live in miserable or disheartening conditions.
- To be neglected; to make little progress, be unsuccessful.
- To make weak; to weaken, devastate.
- To affect a languid air, especially disingenuously.