πρότερον

1 Timothy 1:13 πρότερον formerly

I was formerly a blasphemer, a persecutor, and a violent man; yet because I had acted in ignorance and unbelief, I was shown mercy.

Here: 'Formerly, in the past.' It sets up a clear before-and-after: the man Christ appointed (v.12) was, before that, the man described here.

Hebrews 4:6 πρότερον formerly

Since, then, it remains for some to enter His rest, and since those who formerly heard the good news did not enter because of their disobedience,

Here: "Earlier, back then." It contrasts the wilderness generation with the "we" of 4:2 who now have the good news announced to them. KJV's "first" is acceptable, but the word stresses "earlier" rather than "first in a series."

Hebrews 7:27 πρότερον first

Unlike the other high priests, He does not need to offer daily sacrifices, first for His own sins and then for the sins of the people; He sacrificed for sin once for all when He offered up Himself.

Here: 'First'. It matches the order of Leviticus 16, where the high priest offers a bull for himself and his house before the goat for the people.

Hebrews 10:32 πρότερον former

Remember the early days that you were in the light. In those days, you endured a great conflict in the face of suffering.

Here: An adverb used like an adjective: 'the earlier days.' It looks back to the community's beginnings, implying some time has passed since then.

1 Peter 1:14 πρότερον former

As obedient children, do not conform to the passions of your former ignorance.

Here: 'Previously'. It marks these desires as belonging to a period of life that is now over, the time before their conversion.