The most common and most likely answer to this crossword clue is the 8 letter word HIAWATHA
I've seen this crossword clue in Financial Times
H
I
A
W
A
T
H
A
More clues leading to the result HIAWATHA
- First Nation’s leader, reportedly more senior, with a crumpled hat
- Remain in ditch, shifting one old native chieftain
- Reportedly employ revolting peasant, having arranged initially for 5
- Legendary American greeting unexpected thaw within Alaska’s borders
- Hero of poem, Will’s second, Hathaway, mostly, edited
- Greeting central character in romance — what a fantastic literary hero
- Warrior in a poem written by Longfellow, HW, about a leader of Americans, at his abode, initially
Buddy explains!
The straight part
We know that "old native chieftain" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case old native chieftain = hiawatha.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.