horse-breaker

A MOMENT OF WARの中で色々な人々を描写している個所があります。
I can't, at this length of time, recall all the characters in the group; many are shapes in a shadow play only. I remember Kassell, the boss, thin as a peeled birch tree, with a starved face and fervish eyes. We had Emile, a Dutch professor, hunched and bearded; peachy-cheeked Rafaael, a horse-breaker from Jaen; two tiny Belgians - Jean and Pip - agile and feminine as lemurs; and a dark, silent Catalan we nicknamed Compadre, who may once have been a monk.
業を思い浮かばせるような "horse-breaker" とはどんな職業でしょうか。
・Wordnik: one employed in subduing or training horses for use.
・Collins Dictionary: a person who breaks in a horse
そう言えば "break in" にトレーニングするような意味がありましたね。ついでに、改めて "break in" も確認します。
・Collins Dictionary: to accustom (a person or animal) to normal duties or practice
・Cambridge English Dictionary: If you break someone in, you train them to do a new job or activity
・Macmillan Dictionary: to train a horse that is young or wild
・Wiktionary: (transitive, of a horse) To tame; make obedient; to train to follow orders of the owner.