The antonyms for the phrase "knocking bottom out of" include strengthening, reinforcing, enhancing, supporting, uplifting, and fortifying. These antonyms suggest the opposite of weakening or destroying something or someone. Instead of causing damage, strengthening and reinforcing can help to make something more robust and durable. Enhancing and uplifting suggest increasing the value or quality of something. Supporting means providing assistance or aid to someone, while fortifying implies strengthening against potential threats or challenges. Using these antonyms can help to convey a more positive or constructive meaning, rather than focusing on destruction or harm.