The most common and most likely answer to this crossword clue is the 7 letter word GASPING
I've seen this crossword clue in The Sunday Telegraph
G
A
S
P
I
N
G
More clues leading to the result GASPING
Buddy explains!
The straight part
We know that "desperate for a drink" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case desperate for a drink = gasping.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 GASPING mean?
GASPING verb- To draw in the breath suddenly, as if from a shock.
- To breathe laboriously or convulsively.
- To speak in a breathless manner.
- To pant with eagerness; to show vehement desire.
- The act by which one gasps.
- Very thirsty