Other hyponyms of letter include
ascender,
descender,
digram,
digraph,
initial,
A,
a,
B,
b,
C,
c,
D,
d,
E,
e,
F,
f,
G,
g,
H,
h,
I,
i,
J,
j,
K,
k,
L,
l,
M,
m,
N,
n,
O,
o,
P,
p,
Q,
q,
R,
r,
S,
s,
T,
t,
U,
u,
V,
v,
double-u,
W,
w,
ex,
X,
x,
wye,
Y,
y,
ezed,
izzard,
Z,
z,
zed,
zee,
alpha,
beta,
gamma,
delta,
epsilon,
zeta,
eta,
theta,
iota,
kappa,
lambda,
mu,
nu,
xi,
omicron,
pi,
rho,
sigma,
tau,
upsilon,
phi,
chi,
khi,
psi,
omega,
aleph,
beth,
gimel,
daleth,
he,
waw,
zayin,
heth,
teth,
yodh,
kaph,
lamedh,
mem,
nun,
samekh,
ayin,
pe,
sadhe,
qoph,
resh,
sin,
shin,
taw,
polyphone,
block capital,
block letter,
vowel,
consonant,
yus.