are,

Angels, good or bad. Also, Rulers; royal; those in power or having governing authority, whether heavenly or earthly.
Also, "Divinity; a celestial or invisible being or agent supposed to have dominion over some part of creation; as celestial powers; the powers of darkness."

See more on 'Powers' in Webster's 1828

Put them in mind to be subject to principalities and powers, to obey magistrates, to be ready to every good work, To speak evil of no man, to be no brawlers, but gentle, shewing all meekness unto all men.
Titus 3:1-2

And to make all men see what is the fellowship of the mystery, which from the beginning of the world hath been hid in God, who created all things by Jesus Christ: To the intent that now unto the principalities and powers in heavenly places might be known by the church the manifold wisdom of God, According to the eternal purpose which he purposed in Christ Jesus our Lord...
Ephesians 3:9-11