fiel, faithful, true.
fiera, wild beast.
fiero, fierce, furious.
fiesta, festival, holiday, feast.
Fígaro, prop. noun (the pen-name of Mariano José de Larra, the author of El Castellano viejo).
figura, figure.
figurar (con), to represent (by); —se, to imagine, think.
figurilla, small figure.
fijarse (en), to look (at), notice.