1. deviate from what was planned or expected
the meeting ended up going way off base/script
If you say that someone is way off base it means that they are wrong or incorrect or not aligned with reality. If you are 'way off base' you might make an assumption that is very incorrect. To go off-script means to wing something or to improvise. When you go off script it means you are not reading or saying the words that were agreed and instead make them up. To go 'off script' can mean to say something that was not agreed upon in public or to deviate from a previously made plan or process without informing others.