The antonyms for the word "most straightaway" are delay, detour, and circuitous. Delay means to postpone or put off, while detour refers to a longer route to get somewhere, usually due to an obstacle or road closure. Circuitous means a roundabout or indirect way of reaching a destination. Instead of taking the most straightaway path, these antonyms suggest taking a more indirect route, slowing down or pausing, or taking a different course altogether. Depending on the context, the antonyms of "most straightaway" might be used to suggest caution, thoughtful consideration, or taking a break from the most direct and efficient way.