Antonyms for the term "giving go-ahead" include force to halt, hold back, restrain, impede, hinder, and block. When an individual or group decides to withhold permission or approval, they can cause projects or plans to come to a grinding halt. Holding back also suggests a reluctance to proceed with an idea or proposal, which can impede progress and hinder productivity. Blocking or restraining a proposal indicates a complete opposition to it, and the process cannot continue until the opposition is resolved. In summary, the antonyms for "giving go-ahead" suggest a lack of approval or permission, which can hinder progress and cause projects to come to a standstill.