aikoinaan

Adverb

 * 1) at one time, once; in (its) time

Inflection
Aikoinaan is the third person form of the adverb, which is also inflected in other persons, but unlike some similar adverbs such as mielellään, it may appear in the third person form even when referring to the speaker or their interlocutor: Olin aikoinani hyvä tanssija and Olin aikoinaan hyvä tanssija ("I was a good dancer in my time") are both standard.