The most common and most likely answer to this crossword clue is the 3 letter word CWM
C
W
M
More clues leading to the result CWM
Buddy explains!

The straight part
We know that "Corrie" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case corrie = cwm.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 CWM mean?
CWM noun- A valley head created through glacial erosion and with a shape similar to an amphitheatre.