Wait

Rests for one turn. This is most often used tactically for waiting a few turns. Serious resting should be done with the 5 command, for the sake of your keyboard and sanity. Resting is the only way to get rid of manticore spikes, but is otherwise indistinguishable from any other action; healing, magic point restoration, etc, proceed at the same rate, whether you're resting or not.

To wait is to pass one turn. It may be done by using the s, ., or numpad-5 (try numlock on and off) keys. Waiting works like any other action (such as taking off and putting back on your weapon), though obviously does nothing. Except while slowed, hasted, or under Statue Form, resting it lasts 1 turn (1 decaaut).

Resting (with the regular 5 key) automatically waits until you regenerate health, MP, or find something interesting, like a monster. If you are at full HP and MP, it'll wait up to 100 turns.