The phrase "knock the bottom out of" means to greatly diminish or to destroy something completely. The opposite of this can be to strengthen, rebuild, or restore the item or situation in question. Some antonyms for "knock the bottom out of" include reinforce, secure, fortify, shore up, repair, refurbish, and revive. These words imply that there is potential for the entity to become better than it was before, whereas "knock the bottom out of" is synonymous with complete destruction or failure. By using antonyms, we can create a positive connotation and focus on the potential for growth and change, as opposed to solely emphasizing the negative aspects.