Other hyponyms of letter include
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,
polyphonic letter,
block capital,
block letter,
vowel,
consonant,
yus.