The Spanish have a word for the rivalry and ill-feeling which Jose Mourinho churns up wherever he goes on his successful odyssey through Europe's leading football clubs. Morbo is a feeling which can be positive or negative, which invokes passion and pride.
The rivalry between Barcelona and Real Madrid has much morbo, but the term is usually used in a Spanish only context.
Not tonight. The clash between Real and AC Milan in the Bernabeu is heavily laced with morbo.
The two most successful clubs in European football, with 16 European Cups between them, meet in a Group G leadership contest. The pair met in the 1958 final and have clashed several times in the latter stages of the continent's pre-eminent competition, but the rivalry has more reasons to flourish than ever before.
Mourinho, the Real coach, is the source for much of the depth of feeling. While at Milan's eternal rivals Inter Milan, his personality dominated Italian football as much as his side did.
Milan had goaded Inter fans about their decades without success in the European Cup. Mourinho ended such talk by leading Inter to Champions League glory in May before moving on to his next challenge, that of bringing a 10th European Cup to the Bernabeu.
He recently stated that it was his main aim during the four-year contract he has signed at the club. Real's record in Europe has been as appalling as their penchant for changing coaches in the last six years.
Elimination at the first knock-out stage in each of the last six seasons has seen the giants become figures of fun. They met Milan in the group stage last season, with the Italians recording a memorable first ever victory in the Bernabeu. That was the first nail in the coffin of the managerial career of Manuel Pellegrini in Madrid.
His successor, Mourinho, faced Milan four times as Inter coach and recorded three victories, but he will be wary of incurring the wrath of tonight's referee, Pedro Proenca, who has banished him to the stands on three separate occasions.
And then there is his enmity with Rafa Benitez, the current Inter manager. They regularly goaded each other while at Chelsea and Liverpool, a taunting which continued when Mourinho claimed Benitez has the easiest job in football as he has left him such a great side.
Mourinho, however, does not boast exclusivity on the morbo tonight. Milan's Ronaldinho was a hero at Barca, the best player in the world for much of his five-year spell in Catalunya, so good that the Bernabeu once applauded him for taking Real apart in an el clasico game. The 80,000 crowd hopes that they do not have to stretch to such magnanimity tonight.
One visiting player who might feel unsure about his reception is Zlatan Ibrahimovic. The outspoken Swede scored the winner for Barca against Real last season at Camp Nou and remains Barca's most expensive signing.
At least his comments about Mourinho will carry favour with his old coach after he said: "Mourinho is a winner who stimulated me. [Barca's Pep] Guardiola is nothing."
There are familiar faces for both sets of fans all over the field. Milan's Robinho and Clarence Seedorf both spent three seasons in Madrid, while Real's Kaka spent six years in Italy. His transfer last June angered Milan fans - not least because Kaka said that he was staying in Milan before penning a deal with Real.