Definition of "momentarily"

I imagined momentarily that it was four score and seven years ago, that I had just been brought forth from my mother […]

2010 December 23, Phillip Roth, “Prologue”, in The Great American Novel‎, page 21

The numbers thin out the further we get from London, so I don't feel guilty when I remove my mask momentarily to scoff some of the snacks I'd bought at Marylebone.

2020 December 2, Paul Bigland, “My weirdest and wackiest Rover yet”, in Rail, page 68

He told me, further, that the second coming was at hand--was looked for momentarily in Jerusalem.

1880, Lew Wallace, chapter 3, in Ben-Hur, a Tale of the Christ