"Alit upon" means to land on, settle on or come to a resting place, so antonyms would be verbs that mean the opposite such as take off, depart, rise, ascend, lift off, fly away, shoot up, soar, and mount. These words imply motion, movement, or leaving a place. They convey a sense of action and direction, the opposite of the stillness and immobility of "alit upon." Depending on the context, antonyms for "alit upon" can also include other verbs that imply movement or displacement such as scatter, disperse, shake off, dart away, flee, or vacate. Overall, antonyms for "alit upon" evoke a sense of departure, ascent, and mobility rather than settling or landing on a surface.