letter of the alphabet vs pi

Other hyponyms of letter of the alphabet 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, 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.