Both Uses

tentative
in
The Angel Experiment
(Auto-generated)

I looked down, then sucked in my breath so fast I almost choked. I was standing on a translucent platform suspended high over the sewer system. I wanted to scream, feeling off-balance and scared. ... I swallowed hard and tried to get a grip. Tentatively, I glanced down again at the translucent surface.
p. 123.6 *

tentatively = in an unsure or careful manner
"Was it—was it after the oil-slick Hummer crash?" the Gasman asked Iggy tentatively.†
p. 51.5

Definitions:

(1) (tentative as in: said it tentatively)
done in a careful or unsure way (indicating a lack of confidence in exactly what will happen)
(2) (tentative as in: a tentative plan)
subject to change (likely or possibly going to change)
(3) (meaning too rare to warrant focus)