Shores up is a phrasal verb that means to support, reinforce, or strengthen something, usually a system, structure, organization, or someone's position. The word "antonym" means a word that has the opposite meaning of another word. Thus, the antonyms for "shores up" could be words such as weaken, undermine, sabotage, impair, damage, or hurt. If something is not shored up, it may falter, collapse, fail, or crumble. In contrast, if something is deliberately undermined or sabotaged, it may suffer from intentional harm or destruction. Therefore, understanding the antonyms for "shores up" can help you recognize actions or situations that can weaken or harm your plans, goals, or interests.