edit not a word. Here's my middle letter chart so far
a - BRAIN, TRAIN, STALE, SLATE, TRADE, CHASM, OZARK
b - HABIT
c - RACKS
d - RADIX
e _ FIERY
f - MAFIA, TAFFY, MIFFS
g - RAGER
h - YAHWE
i - DJINN
j - HAJJS
k - HOKIE
l - XYLOL
m - JUMPS
n - IONIC
o - STOLE, STOIC, GHOST
p - (((((ASPEN)))))
q - ZAQAT
r - EERIE, AERIE, HERON
s - UNSET, ROSIE
t - RYTHM
u
v
w - HOWIE
x - PIXIE, NEXUS
y - STYLE, STYLI
z - ZIZIT