Final answer:
The word 'abandon' is most similar in meaning to 'desert', as both involve leaving something behind without the intention of returning.
Step-by-step explanation:
The word abandon is most similar in meaning to the word desert. Both imply leaving something or someone behind, often in a way that suggests a lack of intention to return. For example, if a person abandons their house, they are leaving it and have no plans to come back, which is akin to deserting it. The word change does not convey this sense of leaving, improve is not related as it implies making something better, and loathe means to hate, which is unrelated to the concept of leaving behind.