The most common and most likely answer to this crossword clue is the 8 letter word PLANTERS
I've seen this crossword clue in The Times
P
L
A
N
T
E
R
S
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The straight part
We know that "Old people settling" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case old people settling = planters.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 PLANTERS mean?
PLANTERS noun- One who plants something.
- A box or pot for plants, usually large and standing on the floor.
- Any of the early English settlers, given the lands of the dispossessed Irish populace during the reign of Elizabeth I.
- A machine used for planting seeds.
- The owner of a plantation.