All 3 Uses

resent
in
Tuck Everlasting
(Edited)

Winnie had found some pebbles at the base of the fence and, for lack of any other way to show how she felt, had flung one at the toad. ... and since every pebble missed its final mark, the toad continued to squat and grimace without so much as a twitch. Possibly it felt resentful.
p. 14.3 *

resentful = unhappy about unfair treatment
"You may as well come out," he said, with a frown.
Winnie stood up, embarrassed and, because of that, resentful. "I didn't mean to watch you," she protested as she stepped into the clearing.
p. 26.9

resentful = unhappy about something unfair
The constable stood up. "What did you hit him for?" he wheezed resentfully.
p. 101.9

Definitions:

(1) (resent)
to feel anger or unhappiness about something seen as unjust or something that creates jealousy
(2) (meaning too rare to warrant focus)
Less commonly, resent is another spelling for re-sent; i.e., sent again.