The most common and most likely answer to this crossword clue is the 6 letter word MUKLUK
M
U
K
L
U
K
Buddy explains!

The straight part
We know that "Eskimo's shoe" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case eskimo's shoe = mukluk.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 MUKLUK mean?
MUKLUK noun- A soft knee-high boot of sealskin or reindeer skin, originally worn by Inuit and Yupik.
- A laced winter boot resembling a traditional mukluk, with thick rubber sole and cloth upper.