dit-at-point.el

(require 'popup)
(require 'stem)

(defun dic-find-first (word-list lookup-func)
  (let ((result))
    (catch 'ret
      (while (car word-list)
        (if (setq result (funcall lookup-func (car word-list)))
            (throw 'ret result))
        (setq word-list (cdr word-list))))))

(defun dic-lookup-word (word)
  (let ((description
         (shell-command-to-string (format "dic '%s'" word))))
    (and word
         (not (string= word ""))
         (not (string= description ""))
         description)))

(defun dic-lookup-with-stem (word)
  (let ((word-list (cons word (stem-english word))))
    (dic-find-first word-list 'dic-lookup-word)))

(defun dic-at-point ()
  (interactive)
  (let* ((word (word-at-point))
         (desc (dic-lookup-with-stem word)))
    (when (and desc (null popup-instances))
      (popup-tip desc :margin t))))

(defvar dic-timer nil)
(defvar dic-delay 1.0)
(defvar dic-tip-point nil)

(defun dic-timer ()
  (when (and (not (eq dic-tip-point (point)))
             (not (minibufferp)))
    (setq dic-tip-point (point))
    (dic-at-point)))

(defun dic-start-popup ()
  (interactive)
  (setq dic-timer (run-with-idle-timer dic-delay dic-delay 'dic-timer)))

(defun dic-stop-popup ()
  (interactive)
  (cancel-timer dic-timer)
  (setq dic-timer nil))

(provide 'dic-at-point)