The affection an aficionado has for their favorite subject isn't
merely emotional—it's also etymological. Back in the early 1800s, English
borrowed aficionado from the past participle of the Spanish verb aficionar,
which means "to inspire affection." That verb comes from the Spanish
noun afición, meaning "affection." Both Spanish words trace to the
Latin affectiō (which is also an ancestor of the English word affection).
Affectiō, in turn, is from afficere ("to influence") and gave English
speakers the noun and verb affect.