The antonyms for the word "up-heaves" include settling, stabilizing, calming, pacifying, tranquilizing, and settling down. These words refer to actions that counter the upheaving of something, like the ground or a person's emotions. Settling implies that something was previously chaotic or uncertain and is now becoming peaceful and stable. Stabilizing refers to making something steady or secure, while calming and pacifying involve reducing the intensity of emotions or situations. Lastly, tranquilizing and settling down both imply a sense of stillness or quietness, suggesting that something has reached a state of equilibrium after a period of motion or upheaval.