I'm not entirely happy with 15dn
but I've got a phrase with the meaning "waiting for a place in a part of a hospital" - the 7 letter word works well, but the 3 I'm not so sure of.
21dn has been answered on another thread.
21ac "it makes a vehicle advance"
23dn put "as" and G for german in a wor for "looking well" tp make a city