then (thĕn), adverb [Originally the same word as than. See Than.]

1. At that time (referring to a time specified, either past or future).

And the Canaanite was then in the land. Gen. xii. 6.

Now I know in part; but then shall I know even as also I am known. 1 Cor. xiii. 12

2. Soon afterward, or immediately; next; afterward.

At least to try and teach the erring soul. Milton.First be reconciled to thy brother, and then come and offer thy gift. Matt. v. 24.

3. At another time; later; again.

One while the master is not aware of what is done, and then in other cases it may fall out to be own act. L’Estrange.

By then
(a) By that time.
(b) By the time that.
[Obs.]

But that opinion, I trust, by then this following argument hath been well read, will be left for one of the mysteries of an indulgent Antichrist. Milton.

Now and then

See under Now, adverb

Till then

until that time; until the time mentioned. Milton.

☞ Then is often used elliptically, like an adjective, for then existing; as, the then administration.

Then, conjunction

1. Than. [Obs.] Spenser.

2. In that case; in consequence; as a consequence; therefore; for this reason.

If all this be so, then man has a natural freedom. Locke.

Now, then, be all thy weighty cares away. Dryden.

Syn. – Therefore. Then, Therefore. Both these words are used in reasoning; but therefore takes the lead, while then is rather subordinate or incidental. Therefore states reasons and draws inferences in form; then, to a great extent, takes the point as proved, and passes on to the general conclusion. “Therefore being justified by faith, we have peace with God.” Rom. v. 1. “So then faith cometh by hearing, and hearing by the word of God.” Rom. x. 17.

-- Webster's unabridged 1913