Flyspell-mode

flyspell-mode' Minor mode performing on-the-fly spelling checking. This spawns a single Ispell process and checks each word. The default flyspell behavior is to highlight incorrect words.

flyspell-mode

Description	minor spell checking mode
Author	Manuel Serrano
Maintainer	FSF
Source	http://bzr.savannah.gnu.org/lh/emacs/emacs-24/annotate/head:/lisp/textmodes/flyspell.el
Part of Emacs	yes

Basic setup

(require 'flyspell)
(flyspell-mode +1)

Helpful keybindings

[M-$] (or M-x ispell-word)

correct a word using ispell