kavaliro

There is no seam here, whatever the ending looks like. A learner who has met iri will read kaval-ir-o and try to make it mean "one who goes by horse", which is charmingly close to the truth and completely wrong as word building: Esperanto has no -ir- suffix, and kavalir- is a single borrowed root. The horse connection is genuine but it is Latin history, not Esperanto grammar, and you cannot use it to build anything. Compare banano and naiva, which invite the same over-reading; the article on affix-like roots collects the pattern.

The core sense is the medieval one, the armoured man on horseback, and it extends to a member of an order of chivalry, so a British knight is kavaliro too. The third sense is social rather than historical: a kavaliro is a man behaving with old-fashioned courtesy towards a woman, which is what the last example above is doing. Kavalira means chivalrous and kavalireco is chivalry as a quality.

Do not confuse it with kavalerio, which is cavalry, the branch of an army. Same Latin horse, different Esperanto word, and one letter apart.