From BiblePortal Wikipedia

Vine's Expository Dictionary of NT Words [1]

1: Ἐκεῖθεν (Strong'S #1564 — Adverb — ekeithen — ek-i'-then )

is used (a) of place, e.g.,  Matthew 4:21 , "from thence;"  Matthew 5:26; in  Acts 20:13 , "there;" often preceded by kai, written kakeithen, e.g.,  Mark 9:30;  Luke 11:53 (in the best texts);   Acts 7:4;  14:26; (b) of time,  Acts 13:21 , "and afterward." See After.

 Acts 28:13

King James Dictionary [2]

Thence adv. thens.

1. From that place.

When you depart thence,shake off the dust of your feet.  Mark 6 .

It is more usual, though not necessary, to use from before thence.

Then will I send and fetch thee from thence.  Genesis 27

2. From that time.

There shall be no more thence an infant of days.  Isaiah 65

3. For that reason.

Not to sit idle with so great a gift

Useless, and thence ridiculous, about him.

Webster's Dictionary [3]

(1): ( adv.) Not there; elsewhere; absent.

(2): ( adv.) From that time; thenceforth; thereafter.

(3): ( adv.) For that reason; therefore.

(4): ( adv.) From that place.