The most common and most likely answer to this crossword clue is the 10 letter word ENUMERATOR
I've seen this crossword clue in Financial Times
E
N
U
M
E
R
A
T
O
R
Buddy explains!
The straight part
We know that "census worker" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case census worker = enumerator.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 ENUMERATOR mean?
ENUMERATOR noun- A person who, or a thing that enumerates; a counter or iterator.
- A census taker.