The word 'cappuccino' is the result of several derivations, the original of which began in 16th century. The Capuchin order of friars, established after 1525, played an important role in bringing Catholicism back to Reformation Europe. Its Italian name came from the long, pointed cowl, or cappuccino, derived from cappuccino, "hood," that was worn as part of the order's habit. The French version of cappuccino was capuchin, from which came English Capuchin. In Italian cappuccino went on to describe espresso coffee mixed or topped with steamed milk or cream, so called because the color of the coffee resembled the color of the habit of a Capuchin friar. The first use of cappuccino in English is recorded in 1948 in a work about San Francisco.
There is also the story line that says that the term comes from the fact that the coffee is dark, like the monk's robe, and the cap is likened to the color of the monk's head. ☕️