[5words] 20161217

all of a sudden (B2) = very quickly (used in speaking circumstance)
It seemed to happen all of a sudden - I felt dizzy and I just collapsed.

smitten (a) /ˈsmɪt.ən/  = having suddenly started to like or love something or someone very much:
The story's about a man smitten with love for his wife's cousin.
He was so smitten by her that he promised to move to Argentina to be near her.

insane (a) /ɪnˈseɪn/
(C2) mentally ill:

• For the last ten years of his life he was clinically insane.
• (informal) I sometimes think I'm going insane (= I feel very confused). 

(C1) extremely unreasonable or stupid:

• It would be insane not to take advantage of this opportunity.

cosmopolitan (a) (C1) /ˌkɒz.məˈpɒl.ɪ.tən/ = containing or having experience of people and things from many different parts of the world:

• New York is a highly cosmopolitan city.

off you go
It means to go away and do something, or to start something.
A teacher gives the student a piece of work to complete and says, "off you go."
The teacher means go and complete the work.
Off with your coats.
Out with your books.
Away with your books/phones/mp3-players.
Books away.
Shoes on/off.