Initially such a strange old name for a cathedral city (5)

I believe the answer is:

sarum

I'm a little stuck... Click here to teach me more about this clue!

'old name for a cathedral city' is the definition.
I can't tell whether this definition defines the answer.

'initially such a strange' is the wordplay.
'initially' suggests taking the first letters.
'strange' becomes 'rum' (synonyms).
The first letter of 'such' is 's'.
's'+'a'+'rum'='SARUM'

Can you help me to learn more?

(Other definitions for sarum that I've seen before include "Wiltshire diocese" , "Ancient name of Salisbury" .)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.