What is the meaning of Momentarily?

In a momentary manner; for a moment or instant.

In a moment or very soon; any minute now, any time now.

Progressively; moment by moment.

1 2 3 Just a Moment”, by William Safire, New York Times, May 11, 1997

1 2 3 4 I Stand Corrected: More on Language, by William Safire pp. 137–138

On language, by William Safire, 1980, p. 9

Source: wiktionary.org