Why was Bartolomeo Cristofori's new keyboard instrument called a pianoforte?

The piano was invented by Bartolomeo Cristofori (1655-1731) of Italy. Cristofori was unsatisfied by the lack of control that musicians had over the volume level of the harpsichord. He is credited for switching out the plucking mechanism with a hammer to create the modern piano in around the year 1700.