gualdo - yellow, golden
  guapo - good-looking, attractive, handsome,...
  el guardabosque, la guardabosque - forest ranger, park ranger
  gafe - jinxed
  la gala - big show (often one put on for...
  la gomina - gel (especially hair gel)
  el germen - germ (in most usages)
  la granada - pomegranate, grenade
  el glaciar - glacier
  la falocracia - male chauvinism, male-centered...
  el ferrocarril - railroad, railway, train
  fullero - cheating, dishonest, deceptive,...
  el forro - cover of a book, lining of clothing,...
  la franela - flannel
  la fila - line or row (of objects or people)
  la fotogenia - photogenic quality or qualities
  la furgoneta - van, delivery truck, station wagon
  la foca - seal (animal)
  la fresa - strawberry; a tool that is shaped...
  fehaciente - reliable, irrefutable, dependable,...