sometime

At an indefinite but stated time in the past or future.

I'll see you at the pub sometime this evening.

This will certainly happen sometime in the future.

Sometimes.

At an unstated past or future time; once; formerly.

Did they not sometime cry "All hail" to me?

Former, erstwhile; at some previous time.

my sometime friend and mentor

Therefore our sometime sister, now our queen / Th' imperial jointress to this warlike state

Occasional; intermittent.

an author and sometime lecturer