I'm afraid you have 2dn wrong, so the third letters of 18ac and 21ac aren't as they should be.
In 4dn the wordplay is a word for 'fool' + a word for one of the three parts of the personality in psychoanalytic theory, defn = 'Merry' (poetic)
11ac is a word for 'mothers' containing W (=women), defn = 'dreams' (Scottish)