beginning, corner, (at the, the) first (estate), magistrate, power, principality, principle, rule

“Estate” From Boyd’s Bible Dictionary:

(standing). In Mark 6:21, a class or order representing the government. The “estate of the elders,” Acts 22:5, was a body of advisers cooperating with the Sanhedrim.

“Principality” From Boyd’s Bible Dictionary:

Territory of a prince
Seemingly an order of angels (Eph. 1:21; 6:12; Col. 1:16; 2:10).

Concise Bible Dictionary:

The status of those who hold the first place, as rulers among men (Titus 3:1); but the word especially refers to the spiritual high powers in the unseen world, whether good or bad. They were created by the Lord, and He is head of them all (col. 1:16; Col. 2:10). Some fell from the position of trust given them: they kept not their first estate or principality (Jude 6). Others contend against the heavenly position of the saints (Eph. 6:12). The Lord “spoiled” principalities on the cross (col. 2:15); and at His resurrection He was exalted by God far above all such created powers (Eph. 1:21; Eph. 3:10).

Strong’s Dictionary of Greek Words:

Greek:
ἀρχή
Transliteration:
arche
Phonic:
ar-khay’
Meaning:
from 756; (properly abstract) a commencement, or (concretely) chief (in various applications of order, time, place, or rank)
KJV Usage:
beginning, corner, (at the, the) first (estate), magistrate, power, principality, principle, rule