When input a string in search entry, devhelp will search every time when you input and add a character, even when you input it fast, this is not very convenient. The normal way should be only search after you input over the whole string. Add a timeout to the search entry can solve this problem.

Some example code:
=====
gboolean on_word_change_timeout(gpointer data)
{
    // Do real search.
}

on_entry_changed()
{
    if (word_change_timeout_id) {
        // stop word change timer
        g_source_remove(word_change_timeout_id);
        word_change_timeout_id = 0;
    }
    int word_change_timeout = conf->get_int_at("main_window/word_change_timeout"); // Default 300.
    if(word_change_timeout > 0) {
        word_change_timeout_id = g_timeout_add(word_change_timeout, on_word_change_timeout, NULL);
    } else {
        //Allow word_change_timeout to be 0, so do an immediate search.
        on_word_change_timeout(NULL);
    }
}
=====

A configure in preferences dialog on word_change_timeout would be nice!
StarDict has this feature!

Thanks!