The antonyms for "be solicitous of" are indifference, neglect, disregard, unconcern, and apathy. When one is solicitous of someone or something, they show genuine concern and care. Indifference, on the other hand, is characterized by a lack of concern or interest towards something or someone. Neglect is the act of paying no attention towards someone or something that needs care or attention. Disregard signifies the act of ignoring or disregarding something or someone intentionally. Unconcern is when a person does not care about anything at all. Finally, apathy is defined as a lack of interest, emotion, or motivation towards someone or something.