Something tumescent is puffy or bloated. An overripe peach could be described as tumescent, swollen and bursting with juice.
You'll often find the adjective tumescent describing body parts swelling with sexual excitement, but it can be used for anything that's distended or enlarged. Ripe fruit, puffy hairdos, bloated bellies — all of these are tumescent. Things can be figuratively tumescent too, like an actor's tumescent ego, or overblown, florid, tumescent writing: "I couldn't help giggling when she read her tumescent poetry aloud." The Latin root is tumere, "to swell."