A somewhat old-fashioned or literary word for a particular time, period, or era. Often used in set phrases like その頃おい (at that time) or 若い頃おい (in one's younger days).
At that time, I was still a student.
He talks about memories of his younger days.
Standard spelling for this word; the おい is written in kana to distinguish from the common suffix 頃 (ころ/ごろ).
Variant kanji spelling; rarely used.
Abbreviated spelling; easily confused with the common suffix 頃 (ころ/ごろ).
Abbreviated variant; very rare and ambiguous.
Derived from 頃 (ころ, 'time') + おい (an old suffix possibly related to 生い 'growth' or 追い 'pursuit', but the exact derivation is uncertain). The word is now considered somewhat archaic.