7 letter words
FUNNIER​10
6 letter words (4 words)
FINNER​9
FUNNER​9
UNFINE​9
UNREIN​6
5 letter words (11 words)
INNER​5
URINE​5
FINER​8
INFER​8
RENIN​5
ENNUI​5
NINER​5
INURE​5
ENURN​5
INRUN​5
INURN​5
4 letter words (19 words)
FIRE​7
FINE​7
NINE​4
RUIN​4
FERN​7
RUNE​4
REIN​4
RIFE​7
REIF​7
REFI​7
FIER​7
ENUF​7
RINE​4
NIFE​7
FIRN​7
FENI​7
IURE​4
NEIF​7
NIEF​7
3 letter words (26 words)
RUN​3
FUN​6
INN​3
REF​6
FUR​6
FIN​6
UNI​3
RUE​3
FIR​6
REI​3
REN​3
URN​3
NUR​3
IRE​3
NIE​3
NUN​3
FER​6
RIN​3
FEN​6
URE​3
2 letter words (11 words)
IN​2
IF​5
RE​2
EN​2
UN​2
NE​2
ER​2
FE​5
EF​5
UR​2
NU​2