5 letter words:
fever11,
fifer11,
fiver11,
viper10,
reive8,
4 letter words:
fief10,
fife10,
five10,
riff10,
perv9,
veep9,
ever7,
fere7,
fire7,
free7,
reef7,
reif7,
rife7,
rive7,
veer7,
vier7,
peer6,
pere6,
peri6,
pier6,
pree6,
ripe6,
3 letter words:
eff9,
iff9,
eve6,
fee6,
fer6,
fie6,
fir6,
ref6,
rev6,
rif6,
vee6,
vie6,
pee5,
per5,
pie5,
rep5,
rip5,
ere3,
ire3,
ree3,
rei3,
2 letter words:
ef5,
fe5,
if5,
pe4,
pi4,
er2,
re2,