The most common and most likely answer to this crossword clue is the 8 letter word COLONIST
I've seen this crossword clue in The Times
C
O
L
O
N
I
S
T
More clues leading to the result COLONIST
- Half of capital I invested in rate this man has settled
- Settler : one person held in veneration
- Settler: one individual held in veneration
- Person taking land cut kind of irrigation, by the way
- Horse transporting Chinese from the East, as settler
- Organ is beginning to thrill one who’s settled
- Settler Mark is going to Thailand
- Occupier : is tenant at first
- Settler: one primarily securing territory
- Settler, riding, is carried by young horse
Buddy explains!

The straight part
We know that "Settler" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case settler = colonist.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 COLONIST mean?
COLONIST noun- A founder of a colony.
- A member of a colony.