The most common and most likely answer to this crossword clue is the 4 letter word COWS
I've seen this crossword clue in The Guardian
C
O
W
S
Buddy explains!
The straight part
We know that "is daunting" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case is daunting = cows.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 COWS mean?
COWS noun- (properly) An adult female of the species Bos taurus, especially one that has calved.
- (formerly inexact but now common) Any member of the species Bos taurus regardless of sex or age, including bulls and calves.
- Beef: the meat of cattle as food.
- Any bovines or bovids generally, including yaks, buffalo, etc.
- A female member of other large species of mammal, including the bovines, moose, whales, seals, hippos, rhinos, manatees, and elephants.
- A woman considered unpleasant in some way, particularly one considered nasty, stupid, fat, lazy, or difficult.
- A chock: a wedge or brake used to stop a machine or car.
- A chimney cowl.
- (chiefly in the passive voice) To intimidate; to daunt the spirits or courage of.
- A plant or herb with edible roots, in the genus Lomatium, used in traditional Native American foods and medicines.