The phrase "is open" can be used to describe a variety of situations, from a business that is currently accepting customers to a door or window that is unlocked and accessible. However, there are many synonyms for this phrase that can be used to add variety to your writing and make your descriptions more vibrant. Some examples of synonyms for "is open" include: available, accessible, unsealed, unfastened, unlocked, free, exposed, and unobstructed. Depending on the context, there may be even more specific synonyms that can be used, such as "vacant" for a job position or "public" for a government building. By utilizing different synonyms for "is open," you can make your writing more interesting and engaging.