How to sign: a written message addressed to a person or organization
"mailed an indignant letter to the editor";
Similiar / Same: missive
Categories: document, text, textual matter
Within this category: airmail letter, business letter, chain letter, covering letter, crank letter, dead letter, encyclical, epistle, fan letter, form letter, invitation, letter of intent, open letter, pastoral, personal letter, round robin
How to sign: the conventional characters of the alphabet used to represent speech
"his grandmother taught him his letters";
Similiar / Same: letter of the alphabet, alphabetic character
Categories: character, grapheme, graphic symbol
Within this category: A, aleph, alpha, ascender, ayin, B, beta, beth, block letter, C, chi, consonant, D, daleth, delta, descender, digraph, E, epsilon, eta, F, G, gamma, gimel, H, he, heth, I, initial, iota, J, K, kaph, kappa, L, lambda, lamedh, M, mem, mu, N, nu, nun, O, omega, omicron, P, pe, phi, pi, polyphone, psi, Q, qoph, R, resh, rho, S, sadhe, samekh, shin, sigma, sin, T, tau, taw, teth, theta, U, upsilon, V, vowel, W, waw, X, xi, Y, yodh, Z, zayin, zeta