The phrase "get move on" is often used to urge someone to start moving or to speed up their progress. Some antonyms for this phrase could be to stop, stay put, or slow down. Alternatively, you could consider synonyms for the idea of forward momentum such as advance, proceed, or progress. The opposite of getting a move on could also be to reverse course or retreat. Depending on the context, there may be different ways to express the opposite of getting a move on, whether it's encouraging stillness and reflection or prompting a reversal of direction.