then

[th en] /ðɛn/
adverb
1.
at that time:
Prices were lower then.
2.
immediately or soon afterward:
The rain stopped and then started again.
3.
next in order of time:
We ate, then we started home.
4.
at the same time:
At first the water seemed blue, then gray.
5.
next in order of place:
Standing beside Charlie is my uncle, then my cousin, then my brother.
6.
in addition; besides; also:
I love my job, and then it pays so well.
7.
in that case; as a consequence; in those circumstances:
If you're sick, then you should stay in bed.
8.
since that is so; as it appears; therefore:
You have, then, found the mistake? You are leaving tonight then.
adjective
9.
being; being such; existing or being at the time indicated:
the then prime minister.
noun
10.
that time:
We have not been back since then. Till then, farewell.
Idioms
11.
but then, but on the other hand:
I found their conversation very dull, but then I have different tastes.
12.
then and there, at that precise time and place; at once; on the spot:
I started to pack my things right then and there.
Also, there and then.
Origin
before 900; Middle English then(ne), than(n)e, Old English thonne, thanne, thænne; cf. than; akin to that
Can be confused
than, then (see usage note at than)
Synonyms
8. See therefore.
British Dictionary definitions for then and there

then

/ðɛn/
adverb
1.
at that time; over that period of time
2.
(sentence modifier) in that case; that being so: then why don't you ask her?, if he comes, then you'll have to leave, go on then, take it
3.
then and there, See there (sense 6)
sentence connector
4.
after that; with that: then John left the room and didn't return
noun
5.
that time: before then, from then on
adjective
6.
(prenominal) existing, functioning, etc, at that time: the then prime minister
Word Origin
Old English thenne; related to Old Saxon, Old High German thanna; see than
Word Origin and History for then and there

then

adverb of time, from Old English þanne, þænne, þonne, from Proto-Germanic *thana- (cf. Old Frisian thenne, Old Saxon thanna, Dutch dan, Old High German danne, German dann), from PIE demonstrative pronoun root *to- (see the). For further sense development, see than. Similar evolutions in other Germanic languages; Dutch uses dan in both senses, but German has dann (adv.) "then," denn (conj.) "than." Now and then "at various times" is attested from 1550s; earlier then and then (c.1200).

Idioms and Phrases with then and there

then and there

Also, there and then. At that precise time and place; on the spot. For example, When the board questioned his judgment again, he resigned then and there. The first term was first recorded in 1442, the variant in 1496.