1 at a particular time in the past or future
2 used to say what happens next or what you do next
3a) used when saying what the result of a situation or action will be
b) spoken used when you think that something is probably true because of what you know about the situation
4 but then (again)used to say that although something is true, something else is also true which makes the first thing seem less important
a) used at the beginning of a conversation or activity
b) used at the end of a conversation, especially to show that something has been agreed
c) used to show that you are saying something because of what someone has just said
6 used to add something to what you have just mentioned
7 used to refer back to what you have just been talking about
8 then and there also there and then immediately
only before noun
used when mentioning the person who had a particular job, title, or position at a time in the past
(@ Longman Dictionary of Contemporary English)
I wish I had known then what I know now.
It was then that I realised she'd tricked me.
He started his career in St Petersburg - or Leningrad as it then was.
They're sending out the results next week, so we won't know anything until then.
It was late evening when the doctor arrived, and by then it was too late.
That was in 1970. Since then the place has changed a lot.
They met in 1942 and from then on (=starting at that time) they were firm friends.
Silently she closed the door. Just then she heard a noise.
I was paid £1000, which was a lot of money back then (=a long time ago when things were different) in the 1950s.
Mix the flour and butter, then add the eggs.
Byron travelled to Italy and then to Greece.
If you won't tell him, then I will.
Start off early, then you won't have to rush.
Still in your pyjamas? Have you just got out of bed then?
William didn't succeed first time, but then very few people do.
Elaine's father might lend them the money, but then again he might not.
Now then, what would you like to do today?
Right then, shall we start?
Good, that's settled then. We'll all meet here next Wednesday.
Okay then, I'll see you at work.
'We're late.' 'We'd better hurry, then.'
'Friday's no good.' 'Then how about Saturday?'
We have to invite your parents and my parents, and then there's your brother.
This then was the situation facing the government at the end of the war.
He wasn't prepared to wait - he wanted the money then and there.
(now and then)
a visit to China by the then US President, Richard Nixon