one time

Her eyes would suddenly become fixed on the other side of the room, and for a moment or two she would seem bewildered and absent. One time I was watching her in this state, when her husband took me by the arm and said, 'Come away, Tom.'

1843, George Payne Rainsford James, The Commissioner: Or, De Lunatico Inquirendo, page 186

One time I untied the boat as we were leaving, started to yell Lines off, deckhand on […].

2008, Benjamin Drevlow, Bend with the Knees: And Other Love Advice from My Father, page 14

One time he hadn't held onto himself—the time he worked for the Sedona cattle people up on Oak Creek—and it was the reason he was here.

2009, Elmore Leonard, Forty Lashes Less One, page 24

So, one time, he didn't come back, and didn't come back, and his dinner got cold. When he did come back eventually, he brought a tray of cakes for our girls. Know what I did?” / I shook my head. / “I took the tray from him and threw it all over the garden for the goats and chickens. I was so mad.

2020, Christine Trueman, See You Again, One Time in Saint Helena