The most common and most likely answer to this crossword clue is the 6 letter word FAMINE
F
A
M
I
N
E
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The straight part
We know that "dearth" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case dearth = famine.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 FAMINE mean?
FAMINE noun- Extreme shortage of food in a region.
- A period of extreme shortage of food in a region.
- Starvation or malnutrition.
- Severe shortage or lack of something.