Last couple abandoning fashionable mission (5)

I believe the answer is:

alamo

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

'mission' is the definition.
(famous mission and siege from the Texas revolution)

I don't understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for alamo that I've seen before include "national monument" , "Fort in San Antonio, once famously besieged" , "Site of 1836 massacre in Texas" , "The --, Texan mission besieged in 1836" , "Famous battle in Texas launched by the Mexican army" .)

I've seen this clue in The Telegraph.

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