Madridista

Borrowed from Spanish madridista, from Madrid +‎ -ista.

Madridista (plural Madridistas)

1. (soccer) Someone who plays for Real Madrid CF, a Spanish professional football club based in Madrid.
   • 2021 August 19, Luke McLaughlin, “Football transfer rumours: Robert Lewandowski to exit Bayern Munich?”, in The Guardian‎:

     The deal to sign Martin Ødegaard full-time is also well on the way to becoming reality. Another Madridista, Marco Asensio, is also being touted as a potential target for Mikel Arteta and his sidekick Edu.

2. (soccer) A fan of Real Madrid CF.
   • 2014 April 17, Rob Hughes, “Gloom Gets Darker for Barcelona”, in The New York Times‎:

     It is never only a game when Barça plays Real. Valencia’s Mestalla Stadium is nine decades old, but still it generates a remarkable sensation when 25,000 Catalans are at one end and 25,000 Madridistas fill the other.

3. (soccer) Someone who works for Real Madrid CF.

   (Can we add an example for this sense?)

Madridista

1. elative singular of Madrid